Microsoft symbol server is slow/broken

Question

3 or 4 times in the past 24 hours I have been unable to download symbols from the Microsoft Symbol server, on multiple different development machines (Win 10 and Win 7)

My symbol path is:

symsrv*symsrv.dll*D:\mySymbolCache*http://msdl.microsoft.com/download/symbols

Sometimes it will timeout, sometimes it gets part way through (shown as up to 23% with !sym noisy) before giving up with the message "Incorrect function".

After it gives up, if I try again with:

.reload /f urlmon.dll

and got the following response immediately:

The PDB file is no longer available : ...
The symbol server has a index record for this symbol, but the actual
symbol file no longer exists. This is probably an old build.

This is for urlmon 11.0.10240.16841 from April 9th 2016 - is this symbol really not available?

Is anyone else hitting this problem?

Answer 1

I am having trouble as well. WinDbg & kernel debugging is really broken. It will take forever trying to download symbols -- painfully slow. And if it ever finishes, "lm" will not show any loaded modules other than "nt" making it impossible to debug my code.

If I remove msdl.microsoft.com from the symbol path, at least I can debug again, though without any MS symbols.

Answer 2

I am getting an error message with all modules saying the operation timed out (excluding fltMgr, DUI70, ntoskrnl, ntdll, duser & ntfs are some of the modules that load correctly, as they are cached or are already downloaded), however on Windows 10 the symbols still do download, but it is very slow. Kernel Modules seem to also download as well. !sym noisy also says there is a proxy on my system when there is not one at all.

Here is an example of what loads during a debugging session of StikyNot.exe on Windows 7 x64 7601 using WinDbg 10.0.10586.212 (ran ld* and this is the result):

0:000> lm
start             end                 module name
00000000`76fc0000 00000000`770df000   kernel32   (pdb symbols)          C:\Program Files (x86)\Windows Kits\10\Debuggers\x64\sym\kernel32.pdb\2855B23106B240BEAD0E7E38B19D01032\kernel32.pdb
00000000`770e0000 00000000`771da000   USER32     (pdb symbols)          C:\Program Files (x86)\Windows Kits\10\Debuggers\x64\sym\user32.pdb\270F670F42E94EEC8208EA4E019CDFE42\user32.pdb
00000000`771e0000 00000000`7738b000   ntdll      (pdb symbols)          C:\Program Files (x86)\Windows Kits\10\Debuggers\x64\sym\ntdll.pdb\7A4D6D9790EC4AD38BB281D955A3F87A2\ntdll.pdb
00000000`ff280000 00000000`ff2eb000   StikyNot   (no symbols)           
000007fe`ec890000 000007fe`eca96000   InkObj     (export symbols)       C:\Program Files\Common Files\Microsoft Shared\Ink\InkObj.dll
000007fe`f3f60000 000007fe`f4135000   msxml3     (export symbols)       C:\Windows\System32\msxml3.dll
000007fe`f4610000 000007fe`f46d6000   MSFTEDIT   (export symbols)       C:\Windows\System32\MSFTEDIT.dll
000007fe`f6140000 000007fe`f615d000   mssprxy    (export symbols)       C:\Windows\system32\mssprxy.dll
000007fe`f6270000 000007fe`f63d1000   WindowsCodecs   (export symbols)       C:\Windows\System32\WindowsCodecs.dll
000007fe`f74d0000 000007fe`f7513000   DUser      (pdb symbols)          C:\Program Files (x86)\Windows Kits\10\Debuggers\x64\sym\DUser.pdb\6066E4339825413B88CFBF58855F77732\DUser.pdb
000007fe`f7520000 000007fe`f7612000   DUI70      (pdb symbols)          C:\Program Files (x86)\Windows Kits\10\Debuggers\x64\sym\DUI70.pdb\5E6C1900D2E04D338B6D5989677DDC3E2\DUI70.pdb
000007fe`f9ae0000 000007fe`f9b15000   xmllite    (export symbols)       C:\Windows\system32\xmllite.dll
000007fe`fa2b0000 000007fe`fa2bb000   slc        (export symbols)       C:\Windows\System32\slc.dll
000007fe`fa2e0000 000007fe`fa2f9000   ATL        (export symbols)       C:\Windows\system32\ATL.DLL
000007fe`fb1c0000 000007fe`fb3d6000   gdiplus    (export symbols)       C:\Windows\WinSxS\amd64_microsoft.windows.gdiplus_6595b64144ccf1df_1.1.7601.23508_none_145555328b95eaaa\gdiplus.dll
000007fe`fb680000 000007fe`fb698000   dwmapi     (export symbols)       C:\Windows\System32\dwmapi.dll
000007fe`fb6e0000 000007fe`fb8d4000   COMCTL32   (pdb symbols)          C:\Program Files (x86)\Windows Kits\10\Debuggers\x64\sym\comctl32.pdb\B312550EA9B042F4855C09ADD85020DC1\comctl32.pdb
000007fe`fbed0000 000007fe`fbf26000   UxTheme    (pdb symbols)          C:\Program Files (x86)\Windows Kits\10\Debuggers\x64\sym\UxTheme.pdb\B0692F27B52C454FACA7380C075DE8632\UxTheme.pdb
000007fe`fc460000 000007fe`fc4a7000   rsaenh     (export symbols)       C:\Windows\system32\rsaenh.dll
000007fe`fc760000 000007fe`fc778000   CRYPTSP    (export symbols)       C:\Windows\System32\CRYPTSP.dll
000007fe`fc8b0000 000007fe`fc8d2000   bcrypt     (export symbols)       C:\Windows\System32\bcrypt.dll
000007fe`fcdc0000 000007fe`fcdcf000   CRYPTBASE   (export symbols)       C:\Windows\System32\CRYPTBASE.dll
000007fe`fce70000 000007fe`fce84000   RpcRtRemote   (export symbols)       C:\Windows\System32\RpcRtRemote.dll
000007fe`fcfa0000 000007fe`fd00a000   KERNELBASE   (pdb symbols)          C:\Program Files (x86)\Windows Kits\10\Debuggers\x64\sym\kernelbase.pdb\AE9EAF4EBD744C01A5B8AE94BAEF18552\kernelbase.pdb
000007fe`fd2e0000 000007fe`fd37f000   msvcrt     (export symbols)       C:\Windows\system32\msvcrt.dll
000007fe`fd380000 000007fe`fd583000   ole32      (private pdb symbols)  C:\Program Files (x86)\Windows Kits\10\Debuggers\x64\sym\ole32.pdb\FC5FDFCEF8484FEEA44F26E4F7F611AF2\ole32.pdb
000007fe`fd590000 000007fe`fd66b000   ADVAPI32   (export symbols)       C:\Windows\system32\ADVAPI32.dll
000007fe`fd670000 000007fe`fd69e000   IMM32      (export symbols)       C:\Windows\system32\IMM32.DLL
000007fe`fd980000 000007fe`fd9f1000   SHLWAPI    (pdb symbols)          C:\Program Files (x86)\Windows Kits\10\Debuggers\x64\sym\shlwapi.pdb\0820A0750C1A4E2597E17DEA57D049542\shlwapi.pdb
000007fe`fda00000 000007fe`fda99000   CLBCatQ    (export symbols)       C:\Windows\system32\CLBCatQ.DLL
000007fe`fdaa0000 000007fe`fdbcd000   RPCRT4     (export symbols)       C:\Windows\system32\RPCRT4.dll
000007fe`fe030000 000007fe`fe0fa000   USP10      (export symbols)       C:\Windows\system32\USP10.dll
000007fe`fe100000 000007fe`fe167000   GDI32      (export symbols)       C:\Windows\system32\GDI32.dll
000007fe`fe210000 000007fe`fef9c000   SHELL32    (pdb symbols)          C:\Program Files (x86)\Windows Kits\10\Debuggers\x64\sym\shell32.pdb\A419E0E9F63A4D2B828A00BDD46F0C352\shell32.pdb
000007fe`fefa0000 000007fe`fefbf000   sechost    (export symbols)       C:\Windows\SYSTEM32\sechost.dll
000007fe`ff2f0000 000007fe`ff3f9000   MSCTF      (export symbols)       C:\Windows\system32\MSCTF.dll
000007fe`ff400000 000007fe`ff4d8000   OLEAUT32   (export symbols)       C:\Windows\system32\OLEAUT32.dll
000007fe`ff4e0000 000007fe`ff4ee000   LPK        (export symbols)       C:\Windows\system32\LPK.dll

Answer 3

I'm also have problems !sym noisy shows some interesting errors:

*** ERROR: ERROR_INTERNET_HTTP_TO_HTTPS_ON_REDIR

*** ERROR: HTTP_STATUS_NOT_FOUND

Answer 4

At the moment, I am able to download symbols for combase.dll (10.0.14393.103), but it is running very slow.

0:001> lmDvmcombase
Browse full module list
start             end                 module name
00007ffa`431f0000 00007ffa`434b7000   combase    (deferred)             
    Image path: C:\WINDOWS\System32\combase.dll
    Image name: combase.dll
    Browse all global symbols  functions  data
    Timestamp:        Sat Aug 20 05:56:55 2016 (57B7E317)
    CheckSum:         002CC649
    ImageSize:        002C7000
    File version:     10.0.14393.103
    Product version:  10.0.14393.103
    File flags:       0 (Mask 3F)
    File OS:          40004 NT Win32
    File type:        2.0 Dll
    File date:        00000000.00000000
    Translations:     0409.04b0
    CompanyName:      Microsoft Corporation
    ProductName:      Microsoft® Windows® Operating System
    InternalName:     COMBASE.DLL
    OriginalFilename: COMBASE.DLL
    ProductVersion:   10.0.14393.103
    FileVersion:      10.0.14393.103 (rs1_release_inmarket.160819-1924)
    FileDescription:  Microsoft COM for Windows
    LegalCopyright:   © Microsoft Corporation. All rights reserved.
0:001> x /D /d combase!a*
 A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

SYMSRV:  BYINDEX: 0x3
         D:\Windows Kits\10\Debuggers\x64\sym
         combase.pdb
         33FE217606B5419E82EF1608D92849DD1
SYMSRV:  D:\Windows Kits\10\Debuggers\x64\sym\combase.pdb\33FE217606B5419E82EF1608D92849DD1\combase.pdb - file not found
SYMSRV:  D:\Windows Kits\10\Debuggers\x64\sym\combase.pdb\33FE217606B5419E82EF1608D92849DD1\combase.pdb not found
SYMSRV:  BYINDEX: 0x4
         https://msdl.microsoft.com/download/symbols
         combase.pdb
         33FE217606B5419E82EF1608D92849DD1
SYMSRV:  HTTPGET: /download/symbols/combase.pdb/33FE217606B5419E82EF1608D92849DD1/combase.pdb

SYMSRV:  HttpQueryInfo: 404 - HTTP_STATUS_NOT_FOUND
SYMSRV:  HTTPGET: /download/symbols/combase.pdb/33FE217606B5419E82EF1608D92849DD1/combase.pd_

SYMSRV:  HttpQueryInfo: 200 - HTTP_STATUS_OK
SYMSRV:  D:\Windows Kits\10\Debuggers\x64\sym\combase.pdb\33FE217606B5419E82EF1608D92849DD1\combase.pdb - file not found
SYMSRV:  combase.pdb from https://msdl.microsoft.com/download/symbols: 6398464 bytes -   3 percent

I was also planning to fix a bug in one of my programs today, but because the symbol server is broken, I wont be doing that.

Answer 5

Is anyone else hitting this problem?

I have exactly the same problem. I tried to download symbols with both Visual Studio 2015 and WinDbg (on Windows Server 2012 R2).

Visual Studio did not download anything. It showed me all wrong stacks with a lot of "[Frames below may be incorrect and/or missing, no symbols loaded for ntdll.dll]". When I forced it to download symbols for ntdll.dll, it tried, then it gave up and proposed me to load a local wntdll.dll, which of course I don't have.

WinDbg succeded with some PDBs, but failed with some other PDBs.

For example, it downloaded symbols for ntdll:

77cd0000 77e3f000   ntdll      (pdb symbols)          c:\symbols\wntdll.pdb\238AACDDAEFE41C98EAA92CEB7374AAD2\wntdll.pdb

but it failed for user32:

0:000> .reload /f user32.dll
DBGHELP: C:\Program Files (x86)\Windows Kits\8.1\Debuggers\x86\sym\wuser32.pdb\21DD0941E17849D391B0C7EBEE949F002\wuser32.pdb - file not found
DBGHELP: wuser32.pdb - file not found
*** ERROR: Symbol file could not be found.  Defaulted to export symbols for user32.dll - 
DBGHELP: user32 - export symbols

************* Symbol Loading Error Summary **************
Module name            Error
user32                 The PDB file is no longer available : srv*c:\symbols*http://msdl.microsoft.com/download/symbols
The symbol server has a index record for this symbol, but the actual
symbol file no longer exists. This is probably an old build.

Answer 6

I'm having the same problem as everyone else here loading symbols.  I'm doing it through the Visual Studio debugger, but the symptoms are the same - it's very, very slow and sometimes the symbols don't even load.

Answer 7

We're aware of the current download speeds from the Microsoft symbol server and are actively working on a fix.

EDIT: We've got a fix deployed that should be mitigating the problem for most users.

Answer 8

Thank you for the communication Andy!

Answer 9

Thanks, yes, it's been horrible since last week. So hopefully a resolution will be soon.

Not fun being subject to DDOS  (Developer Denial of Service).

I hate to think of the impact on productivity this has had world wide.

So far it's been greater than a week since we first started having delays.

Answer 10

Same here at TechSmith in Okemos, MI.  We first noticed problems last Friday, Sept 2.  Multiple team members are still seeing extremely slow downloads today (Tuesday, Sept 6) from http://msdl.microsoft.com/download/symbols using both Visual Studio 2015 and WinDbg.

@Andy Luhrs, thanks for confirming the problem.  Please keep us updated.

Answer 11

I've also only just noticed HTTP error 406 HTTP_STATUS_NONE_ACCEPTABLE whilst downloading symbols in any program that uses DbgHelp.dll as of 07/09/2016:

SETUPAPI.dll (10.0.14393.0) fails along with all other undownloaded modules:

SYMSRV:  BYINDEX: 0x15
         d:\windows kits\10\debuggers\x64\sym
         setupapi.pdb
         D0946C7C68BB48DA8D070CE599893AF81
SYMSRV:  d:\windows kits\10\debuggers\x64\sym\setupapi.pdb\D0946C7C68BB48DA8D070CE599893AF81\setupapi.pdb - file not found
SYMSRV:  d:\windows kits\10\debuggers\x64\sym\setupapi.pdb\D0946C7C68BB48DA8D070CE599893AF81\setupapi.pdb not found
SYMSRV:  BYINDEX: 0x16
         D:\Windows Kits\10\Debuggers\x64\sym
         setupapi.pdb
         D0946C7C68BB48DA8D070CE599893AF81
SYMSRV:  D:\Windows Kits\10\Debuggers\x64\sym\setupapi.pdb\D0946C7C68BB48DA8D070CE599893AF81\setupapi.pdb - file not found
SYMSRV:  D:\Windows Kits\10\Debuggers\x64\sym\setupapi.pdb\D0946C7C68BB48DA8D070CE599893AF81\setupapi.pdb not found
SYMSRV:  BYINDEX: 0x17
         https://msdl.microsoft.com/download/symbols
         setupapi.pdb
         D0946C7C68BB48DA8D070CE599893AF81
SYMSRV:  HTTPGET: /download/symbols/setupapi.pdb/D0946C7C68BB48DA8D070CE599893AF81/setupapi.pdb

SYMSRV:  HttpQueryInfo: 406 - HTTP_STATUS_NONE_ACCEPTABLE
SYMSRV:  D:\Windows Kits\10\Debuggers\x64\sym\setupapi.pdb\D0946C7C68BB48DA8D070CE599893AF81\setupapi.pdb - file not found
SYMSRV:  https://msdl.microsoft.com/download/symbols/setupapi.pdb/D0946C7C68BB48DA8D070CE599893AF81/setupapi.pdb not found
SYMSRV:  D:\Windows Kits\10\Debuggers\x64\sym\setupapi.pdb\D0946C7C68BB48DA8D070CE599893AF81\setupapi.pdb not found
DBGHELP: C:\WINDOWS\System32\setupapi.pdb - file not found
DBGHELP: setupapi.pdb - file not found
*** ERROR: Symbol file could not be found.  Defaulted to export symbols for C:\WINDOWS\System32\SETUPAPI.dll - 
DBGHELP: SETUPAPI - export symbols

For some modules however they will not export:

luafv.sys (10.0.14393.0)
SYMSRV:  BYINDEX: 0x2E
         d:\windows kits\10\debuggers\x64\sym
         luafv.pdb
         FE8BCE979E544ABE9CC395523EE78CD31
SYMSRV:  d:\windows kits\10\debuggers\x64\sym\luafv.pdb\FE8BCE979E544ABE9CC395523EE78CD31\luafv.pdb - file not found
SYMSRV:  d:\windows kits\10\debuggers\x64\sym\luafv.pdb\FE8BCE979E544ABE9CC395523EE78CD31\luafv.pdb not found
DBGHELP: luafv.pdb - file not found
*** ERROR: Module load completed but symbols could not be loaded for luafv.sys
DBGHELP: luafv - no symbols loaded

However some work fine like FLTMGR.SYS (10.0.14393.0) as they have been stored in the cache when the speeds were slow:

SYMSRV:  BYINDEX: 0x2A
         d:\windows kits\10\debuggers\x64\sym
         fltMgr.pdb
         5ED9B0440F254A29975A7EC0954875F71SYMSRV:  PATH: d:\windows kits\10\debuggers\x64\sym\fltMgr.pdb\5ED9B0440F254A29975A7EC0954875F71\fltMgr.pdb

DBGHELP: FLTMGR - public symbols  
        d:\windows kits\10\debuggers\x64\sym\fltMgr.pdb\5ED9B0440F254A29975A7EC0954875F71\fltMgr.pdb

Answer 12

I am also getting HTTP 406 errors, very frustrating I am unable to download any symbols. 

UK here if that helps.

Answer 13

Hi Andy, Issue looks to be resolved on my end!

Answer 14

I'm downloading symbols but it's going about 1Mbps. Based in Vancouver, Canada FWIW

Answer 15

The issue seems to be fixed:

SYMSRV:  BYINDEX: 0xD
         d:\windows kits\10\debuggers\x64\sym
         shell32.pdb
         209066F569A94634ABD929FCB63A2AEF1
SYMSRV:  d:\windows kits\10\debuggers\x64\sym\shell32.pdb\209066F569A94634ABD929FCB63A2AEF1\shell32.pdb - file not found
SYMSRV:  d:\windows kits\10\debuggers\x64\sym\shell32.pdb\209066F569A94634ABD929FCB63A2AEF1\shell32.pdb not found
SYMSRV:  BYINDEX: 0xE
         D:\Windows Kits\10\Debuggers\x64\sym
         shell32.pdb
         209066F569A94634ABD929FCB63A2AEF1
SYMSRV:  D:\Windows Kits\10\Debuggers\x64\sym\shell32.pdb\209066F569A94634ABD929FCB63A2AEF1\shell32.pdb - file not found
SYMSRV:  D:\Windows Kits\10\Debuggers\x64\sym\shell32.pdb\209066F569A94634ABD929FCB63A2AEF1\shell32.pdb not found
SYMSRV:  BYINDEX: 0xF
         https://msdl.microsoft.com/download/symbols
         shell32.pdb
         209066F569A94634ABD929FCB63A2AEF1
SYMSRV:  HTTPGET: /download/symbols/shell32.pdb/209066F569A94634ABD929FCB63A2AEF1/shell32.pdb

SYMSRV:  HttpQueryInfo: 404 - HTTP_STATUS_NOT_FOUND
SYMSRV:  HTTPGET: /download/symbols/shell32.pdb/209066F569A94634ABD929FCB63A2AEF1/shell32.pd_

SYMSRV:  HttpQueryInfo: 200 - HTTP_STATUS_OK
SYMSRV:  D:\Windows Kits\10\Debuggers\x64\sym\shell32.pdb\209066F569A94634ABD929FCB63A2AEF1\shell32.pdb - file not found
SYMSRV:  shell32.pdb from https://msdl.microsoft.com/download/symbols: 1785126 bytes - copied         
SYMSRV:  PATH: D:\Windows Kits\10\Debuggers\x64\sym\shell32.pdb\209066F569A94634ABD929FCB63A2AEF1\shell32.pdb
DBGHELP: D:\Windows Kits\10\Debuggers\x64\sym\shell32.pdb\209066F569A94634ABD929FCB63A2AEF1\shell32.pdb already cached
DBGHELP: D:\Windows Kits\10\Debuggers\x64\sym\shell32.pdb\209066F569A94634ABD929FCB63A2AEF1\shell32.pdb already cached

DBGHELP: SHELL32 - public symbols  
        D:\Windows Kits\10\Debuggers\x64\sym\shell32.pdb\209066F569A94634ABD929FCB63A2AEF1\shell32.pdb

Answer 16

The issue seems to be resolved for us too.  Thanks for the help.

Answer 17

Sadly it's slow again.  Trying to use WinDbg and we're watching the paint dry.

Isn't there a way to monitor this so developers can continue to be productive?

Keith

Answer 18

Painfully slow! What is going on?

Answer 19

have the same slow issues - sometime very slow since two days - does it may depend on the used symsrv.dll & dbghelp.dll versions which is not in all cases the latest one delivered with VS2105 ?

Answer 20

10/18 and sadly this is still an issue.  Anyone have info on when it will be resolved?

Can hardly use WinDbg.

Answer 21

10/18 and sadly this is still an issue.  Anyone have info on when it will be resolved?

Can hardly use WinDbg.

Same here, today is 10/18/2016 and we are using WPA and spent hours loading symbols (still going on and not finished) and got lots of HTTP_STATUS_NOT_FOUND, this severely blocks our work, Andy Luhrs please help!!

Answer 22

Same here. It is painfully slow.

Answer 23

It seems a little bit better today... but still terribly slow...

Answer 24

10/18 and sadly this is still an issue.  Anyone have info on when it will be resolved?

Can hardly use WinDbg.

Same here, today is 10/18/2016 and we are using WPA and spent hours loading symbols (still going on and not finished) and got lots of HTTP_STATUS_NOT_FOUND, this severely blocks our work, Andy Luhrs please help!!

3 days later and the problem remains...

Answer 25

We have the same problem here.

Answer 26

I'm also having issues downloading some but not all files, visual studio takes ages to initialise the debugger as it retries downloading about 10 different symbol files.

Answer 27

Yes. The Symbol server has been going very slow for me the last week or so. It's unbearable. I've unchecked hitting the Microsoft servers cause it's unusable. But, before doing that, I cleared all my cached locations hoping it was just a corrupted symbol cache on my end. But that didn't help.

Microsoft, are you aware of any problems on your end with the symbol servers?

Answer 28

I have been having the same problem since a long time ago.

Answer 29

Make sure you're using https:

https://msdl.microsoft.com/download/symbols

Could be just a coincidence, but that fixed it for me.

Answer 30

Still getting a 404 http error for all pdb files in WPA (windows performance analyzer). Changed to https but didn't work.

Just downloading symbols for local installation from

https://developer.microsoft.com/en-us/windows/hardware/download-symbols

---

Armin

Answer 31

For example, my ntdll.dll is from 10/25/2016, so is it possible, the latest pdb files just haven't been published yet?

---

Armin

Answer 32

I'm in the exact same boat, fresh install of windows 10 and fully updated. 

Answer 33

Symbols for 14393.447 were never put on the server yet.

You should use !sym noisy to figure out what the actual issue is, or use symchk with /v

Answer 34

Thanks Nick, using symchk, I get this output:

C:\Program Files\Debugging Tools for Windows (x64)>symchk /if c:\windows\system32\ntdll.dll /v
[SYMCHK] Searching for symbols to c:\windows\system32\ntdll.dll in path SRV*D:\Symbols*http://msdl.microsoft.com/download/symbols
DBGHELP: Symbol Search Path: SRV*D:\Symbols*http://msdl.microsoft.com/download/symbols
[SYMCHK] Using search path "SRV*D:\Symbols*http://msdl.microsoft.com/download/symbols"
DBGHELP: No header for c:\windows\system32\ntdll.dll.  Searching for image on disk
DBGHELP: c:\windows\system32\ntdll.dll - OK
SYMSRV:  D:\Symbols\ntdll.pdb\EBACFB2C299D49E1BFDC3EB3F9E6B2191\ntdll.pdb not found
SYMSRV:  http://msdl.microsoft.com/download/symbols/ntdll.pdb/EBACFB2C299D49E1BFDC3EB3F9E6B2191/ntdll.pdb not found
DBGHELP: ntdll - no symbols loaded
[SYMCHK] MODULE64 Info ----------------------
[SYMCHK] Struct size: 1672 bytes
[SYMCHK] Base: 0x0000000180000000
[SYMCHK] Image size: 1839104 bytes
[SYMCHK] Date: 0x580ee321
[SYMCHK] Checksum: 0x001ca40b
[SYMCHK] NumSyms: 0
[SYMCHK] SymType: SymNone
[SYMCHK] ModName: ntdll
[SYMCHK] ImageName: c:\windows\system32\ntdll.dll
[SYMCHK] LoadedImage: c:\windows\system32\ntdll.dll
[SYMCHK] PDB: ""
[SYMCHK] CV: RSDS
[SYMCHK] CV DWORD: 0x53445352
[SYMCHK] CV Data:  ntdll.pdb
[SYMCHK] PDB Sig:  0
[SYMCHK] PDB7 Sig: {00000000-0000-0000-0000-000000000000}
[SYMCHK] Age: 0
[SYMCHK] PDB Matched:  TRUE
[SYMCHK] DBG Matched:  TRUE
[SYMCHK] Line nubmers: FALSE
[SYMCHK] Global syms:  FALSE
[SYMCHK] Type Info:    FALSE
[SYMCHK] ------------------------------------
SymbolCheckVersion  0x00000002
Result              0x00010001
DbgFilename         ntdll.dbg
DbgTimeDateStamp    0x00000000
DbgSizeOfImage      0x00000000
DbgChecksum         0x00000000
PdbFilename         ntdll.pdb
PdbSignature        {EBACFB2C-299D-49E1-BFDC-3EB3F9E6B219}
PdbDbiAge           0x00000001
[SYMCHK] [ 0x00000000 - 0x00010001 ] Checked "c:\windows\system32\ntdll.dll"
SYMCHK: ntdll.dll            FAILED  - ntdll.pdb mismatched or not found

SYMCHK: FAILED files = 1
SYMCHK: PASSED + IGNORED files = 0

EDIT: In Windbg, with sym noisy, I get a 404 for the file (equal to WPA that I'm actually using)

---

Armin

Answer 35

It seems, couple of symbol files (127) have been added today. Several of them are Microsoft.VisualStudio.*.pdb. Not the ones I'm waiting for, but it looks promising, so let's wait....

(EDIT: and more are being added currently..)

---

Armin

Answer 36

For example, my ntdll.dll is from 10/25/2016, so is it possible, the latest pdb files just haven't been published yet?

---

Armin

I think this is because the NTFS metadata is also copied with the file update during a Windows update. So for instance, ntdll last modify time on disk isn't necessarily going to reflect the same day you updated that machine.

Answer 37

Sure, but my point was that it obviously takes more than 3 weeks for MSFT to update the symbol server.

---

Armin

Answer 38

There exists a Visual Studio Connect report regarding missing symbols for Windows 10 14393.447 at
https://connect.microsoft.com/VisualStudio/feedback/details/3111673
which you probably may want to vote up.

With kind regards

Answer 39

Hi MaybeCompletelyW, thanks for the hint! :) Voted.

---

Armin

Answer 40

Server is responding now!

Answer 41

My problem wasn't the server is not responding but that important symbol files are still missing. Let's wait and hope...

---

Armin

Answer 42

Hey, new symbols are arriving on the server! :) That's great. At least for my beloved ntdll.dll they are there now. ;)

EDIT: ...and it's fast now!

EDIT #2: Spoke too soon. :( I've upgraded to Win10 version 1607 today and received a new ntdll.dll with it. For this one, the symbols are there on the symbol server. However, I need the symbols for the older ntdll.dll. (hash EBACFB2C299D49E1BFDC3EB3F9E6B2191)

---

Armin

Answer 43

The same issue here :( On new win 10 computer.

SYMSRV:  BYINDEX: 0x17
         C:\ProgramData\dbg\sym
         ntdll.pdb
         309B7D2A275C49A1917EC6033A73D0ED1
SYMSRV:  C:\ProgramData\dbg\sym\ntdll.pdb\309B7D2A275C49A1917EC6033A73D0ED1\ntdll.pdb - file not found
SYMSRV:  C:\ProgramData\dbg\sym\ntdll.pdb\309B7D2A275C49A1917EC6033A73D0ED1\ntdll.pdb not found
SYMSRV:  BYINDEX: 0x18
         https://msdl.microsoft.com/download/symbols
         ntdll.pdb
         309B7D2A275C49A1917EC6033A73D0ED1
SYMSRV:  HTTPGET: /download/symbols/ntdll.pdb/309B7D2A275C49A1917EC6033A73D0ED1/ntdll.pdb

SYMSRV:  HttpQueryInfo: 502 - HTTP_STATUS_BAD_GATEWAY
SYMSRV:  C:\ProgramData\dbg\sym\ntdll.pdb\309B7D2A275C49A1917EC6033A73D0ED1\ntdll.pdb - file not found
SYMSRV:  https://msdl.microsoft.com/download/symbols/ntdll.pdb/309B7D2A275C49A1917EC6033A73D0ED1/ntdll.pdb not found
SYMSRV:  C:\ProgramData\dbg\sym\ntdll.pdb\309B7D2A275C49A1917EC6033A73D0ED1\ntdll.pdb not found
DBGHELP: ntdll.pdb - file not found
*** ERROR: Symbol file could not be found.  Defaulted to export symbols for ntdll.dll - 
DBGHELP: ntdll - export symbols

Is there any workaround? :(

Btw I tried symchk /if c:\windows\system32\ntdll.dll /v

but it complaints Couldn't resolve error at 'ymchk /if c:\windows\system32\ntdll.dll /v''. Is the syntax wrong?

Answer 44

Same error is occurring on Windows 7 x64. Almost all symbol loads have failed with error HTTP 502. Here is an example:

0:000> lml
start             end                 module name
00000000`76b00000 00000000`76c1f000   kernel32   (export symbols)       C:\Windows\system32\kernel32.dll
00000000`76d20000 00000000`76eca000   ntdll      (export symbols)       C:\Windows\SYSTEM32\ntdll.dll
00000001`3f3c0000 00000001`3f3ca000   DbgCall  C (private pdb symbols)  C:\Program Files (x86)\Windows Kits\10\Debuggers\x64\sym\DbgCall.pdb\4DC36D6D9E804D8F8713B61C628CF73B3\DbgCall.pdb (locally stored on computer as it is a program I have written)
000007fe`ec230000 000007fe`ec2ce000   MSVCP140   (export symbols)       C:\Windows\system32\MSVCP140.dll
000007fe`f33e0000 000007fe`f33e3000   api_ms_win_crt_locale_l1_1_0   (export symbols)       C:\Windows\system32\api-ms-win-crt-locale-l1-1-0.dll
000007fe`f33f0000 000007fe`f33f5000   api_ms_win_crt_math_l1_1_0   (export symbols)       C:\Windows\system32\api-ms-win-crt-math-l1-1-0.dll
000007fe`f3400000 000007fe`f3404000   api_ms_win_crt_convert_l1_1_0   (export symbols)       C:\Windows\system32\api-ms-win-crt-convert-l1-1-0.dll
000007fe`f3410000 000007fe`f3414000   api_ms_win_crt_stdio_l1_1_0   (export symbols)       C:\Windows\system32\api-ms-win-crt-stdio-l1-1-0.dll
000007fe`f3420000 000007fe`f3514000   ucrtbase   (pdb symbols)          C:\Program Files (x86)\Windows Kits\10\Debuggers\x64\sym\ucrtbase.pdb\874D0FF93A41440A81AD07F07CFC561C1\ucrtbase.pdb
000007fe`f3cf0000 000007fe`f3cf3000   api_ms_win_crt_heap_l1_1_0   (export symbols)       C:\Windows\system32\api-ms-win-crt-heap-l1-1-0.dll
000007fe`f3d00000 000007fe`f3d04000   api_ms_win_crt_string_l1_1_0   (export symbols)       C:\Windows\system32\api-ms-win-crt-string-l1-1-0.dll
000007fe`f3d10000 000007fe`f3d13000   api_ms_win_core_file_l1_2_0   (export symbols)       C:\Windows\system32\api-ms-win-core-file-l1-2-0.dll
000007fe`f3d20000 000007fe`f3d23000   api_ms_win_core_processthreads_l1_1_1   (export symbols)       C:\Windows\system32\api-ms-win-core-processthreads-l1-1-1.dll
000007fe`f3d30000 000007fe`f3d33000   api_ms_win_core_localization_l1_2_0   (export symbols)       C:\Windows\system32\api-ms-win-core-localization-l1-2-0.dll
000007fe`f3d40000 000007fe`f3d43000   api_ms_win_core_file_l2_1_0   (export symbols)       C:\Windows\system32\api-ms-win-core-file-l2-1-0.dll
000007fe`f46c0000 000007fe`f46c3000   api_ms_win_core_timezone_l1_1_0   (export symbols)       C:\Windows\system32\api-ms-win-core-timezone-l1-1-0.dll
000007fe`f46d0000 000007fe`f46d4000   api_ms_win_crt_runtime_l1_1_0   (export symbols)       C:\Windows\system32\api-ms-win-crt-runtime-l1-1-0.dll
000007fe`f76a0000 000007fe`f76b7000   VCRUNTIME140   (export symbols)       C:\Windows\system32\VCRUNTIME140.dll
000007fe`f8b60000 000007fe`f8b63000   api_ms_win_crt_environment_l1_1_0   (export symbols)       C:\Windows\system32\api-ms-win-crt-environment-l1-1-0.dll
000007fe`f8b70000 000007fe`f8b75000   api_ms_win_crt_multibyte_l1_1_0   (export symbols)       C:\Windows\system32\api-ms-win-crt-multibyte-l1-1-0.dll
000007fe`f8be0000 000007fe`f8be3000   api_ms_win_crt_utility_l1_1_0   (export symbols)       C:\Windows\system32\api-ms-win-crt-utility-l1-1-0.dll
000007fe`f8e60000 000007fe`f8e63000   api_ms_win_crt_filesystem_l1_1_0   (export symbols)       C:\Windows\system32\api-ms-win-crt-filesystem-l1-1-0.dll
000007fe`fb630000 000007fe`fb633000   api_ms_win_core_synch_l1_2_0   (export symbols)       C:\Windows\system32\api-ms-win-core-synch-l1-2-0.dll
000007fe`fb890000 000007fe`fb893000   api_ms_win_crt_time_l1_1_0   (export symbols)       C:\Windows\system32\api-ms-win-crt-time-l1-1-0.dll
000007fe`fcd30000 000007fe`fcd9a000   KERNELBASE   (export symbols)       C:\Windows\system32\KERNELBASE.dll
000007fe`fcfd0000 000007fe`fd06f000   msvcrt     (pdb symbols)          C:\Program Files (x86)\Windows Kits\10\Debuggers\x64\sym\msvcrt.pdb\5376EFB7D7E54B4DA4156FF73543E6B02\msvcrt.pdb
000007fe`fd070000 000007fe`fd19d000   RPCRT4     (export symbols)       C:\Windows\system32\RPCRT4.dll
000007fe`fdde0000 000007fe`fddff000   sechost    (pdb symbols)          C:\Program Files (x86)\Windows Kits\10\Debuggers\x64\sym\sechost.pdb\3824AD19AB6C47AA8870D6E371F1738B1\sechost.pdb
000007fe`fdf00000 000007fe`fdfdb000   ADVAPI32   (export symbols)       C:\Windows\system32\ADVAPI32.dll
0:000> .reload
Reloading current modules
.............................
SYMSRV:  BYINDEX: 0x64
         C:\Program Files (x86)\Windows Kits\10\Debuggers\x64\sym
         ntdll.pdb
         07AEB673B5B043C1A37ADEA4DD57D2482
SYMSRV:  C:\Program Files (x86)\Windows Kits\10\Debuggers\x64\sym\ntdll.pdb\07AEB673B5B043C1A37ADEA4DD57D2482\ntdll.pdb - file not found
SYMSRV:  C:\Program Files (x86)\Windows Kits\10\Debuggers\x64\sym\ntdll.pdb\07AEB673B5B043C1A37ADEA4DD57D2482\ntdll.pdb not found
SYMSRV:  BYINDEX: 0x65
         https://msdl.microsoft.com/download/symbols
         ntdll.pdb
         07AEB673B5B043C1A37ADEA4DD57D2482
SYMSRV:  HTTPGET: /download/symbols/ntdll.pdb/07AEB673B5B043C1A37ADEA4DD57D2482/ntdll.pdb
SYMSRV:  HttpQueryInfo: 502 - HTTP_STATUS_BAD_GATEWAY
SYMSRV:  C:\Program Files (x86)\Windows Kits\10\Debuggers\x64\sym\ntdll.pdb\07AEB673B5B043C1A37ADEA4DD57D2482\ntdll.pdb - file not found
SYMSRV:  https://msdl.microsoft.com/download/symbols/ntdll.pdb/07AEB673B5B043C1A37ADEA4DD57D2482/ntdll.pdb not found
SYMSRV:  C:\Program Files (x86)\Windows Kits\10\Debuggers\x64\sym\ntdll.pdb\07AEB673B5B043C1A37ADEA4DD57D2482\ntdll.pdb not found
DBGHELP: C:\Windows\SYSTEM32\ntdll.pdb - file not found
DBGHELP: ntdll.pdb - file not found
*** ERROR: Symbol file could not be found.  Defaulted to export symbols for ntdll.dll - 
DBGHELP: ntdll - export symbols
SYMSRV:  BYINDEX: 0x66
         C:\Program Files (x86)\Windows Kits\10\Debuggers\x64\sym
         DbgCall.pdb
         4DC36D6D9E804D8F8713B61C628CF73B3
SYMSRV:  PATH: C:\Program Files (x86)\Windows Kits\10\Debuggers\x64\sym\DbgCall.pdb\4DC36D6D9E804D8F8713B61C628CF73B3\DbgCall.pdb
DBGHELP: C:\Program Files (x86)\Windows Kits\10\Debuggers\x64\sym\DbgCall.pdb\4DC36D6D9E804D8F8713B61C628CF73B3\DbgCall.pdb already cached
DBGHELP: C:\Program Files (x86)\Windows Kits\10\Debuggers\x64\sym\DbgCall.pdb\4DC36D6D9E804D8F8713B61C628CF73B3\DbgCall.pdb already cached
*** WARNING: Unable to verify checksum for DbgCall.exe
DBGHELP: DbgCall - private symbols & lines 
        C:\Program Files (x86)\Windows Kits\10\Debuggers\x64\sym\DbgCall.pdb\4DC36D6D9E804D8F8713B61C628CF73B3\DbgCall.pdb

************* Symbol Loading Error Summary **************
Module name            Error
ntdll                  PDB not found : cache*
Unable to locate the .pdb file in this location

                       An extended error was returned from the WinHttp server : SRV*https://msdl.microsoft.com/download/symbols
The .pdb file is probably no longer indexed in the symbol server share location.
Please verify that you have access to the symbol server from your location.

Answer 45

And the same happens with a kernel error (also Windows 7 x64):

0: kd> .symfix
DBGHELP: Symbol Search Path: cache*;SRV*https://msdl.microsoft.com/download/symbols
DBGHELP: Symbol Search Path: cache*;SRV*https://msdl.microsoft.com/download/symbols
DBGHELP: Symbol Search Path: cache*;SRV*https://msdl.microsoft.com/download/symbols
0: kd> .reload
SYMSRV:  BYINDEX: 0xCB
         C:\Program Files (x86)\Windows Kits\10\Debuggers\x64\sym
         ntkrnlmp.pdb
         A08016714A2A4278B80FDCD90CD5957B2
SYMSRV:  C:\Program Files (x86)\Windows Kits\10\Debuggers\x64\sym\ntkrnlmp.pdb\A08016714A2A4278B80FDCD90CD5957B2\ntkrnlmp.pdb - file not found
SYMSRV:  C:\Program Files (x86)\Windows Kits\10\Debuggers\x64\sym\ntkrnlmp.pdb\A08016714A2A4278B80FDCD90CD5957B2\ntkrnlmp.pdb not found
SYMSRV:  BYINDEX: 0xCC
         https://msdl.microsoft.com/download/symbols
         ntkrnlmp.pdb
         A08016714A2A4278B80FDCD90CD5957B2
SYMSRV:  HTTPGET: /download/symbols/ntkrnlmp.pdb/A08016714A2A4278B80FDCD90CD5957B2/ntkrnlmp.pdb
SYMSRV:  HttpQueryInfo: 502 - HTTP_STATUS_BAD_GATEWAY
SYMSRV:  C:\Program Files (x86)\Windows Kits\10\Debuggers\x64\sym\ntkrnlmp.pdb\A08016714A2A4278B80FDCD90CD5957B2\ntkrnlmp.pdb - file not found
SYMSRV:  https://msdl.microsoft.com/download/symbols/ntkrnlmp.pdb/A08016714A2A4278B80FDCD90CD5957B2/ntkrnlmp.pdb not found
SYMSRV:  C:\Program Files (x86)\Windows Kits\10\Debuggers\x64\sym\ntkrnlmp.pdb\A08016714A2A4278B80FDCD90CD5957B2\ntkrnlmp.pdb not found
DBGHELP: ntkrnlmp.pdb - file not found
*** ERROR: Symbol file could not be found.  Defaulted to export symbols for ntkrnlmp.exe - 
DBGHELP: nt - export symbols
Loading Kernel Symbols
...............................................................
................................................................
......................
Loading User Symbols

Loading unloaded module list
......
SYMSRV:  BYINDEX: 0xCD
         C:\Program Files (x86)\Windows Kits\10\Debuggers\x64\sym
         fltMgr.pdb
         A008BBBF87CC421FA0E568076A16F4BA2
SYMSRV:  PATH: C:\Program Files (x86)\Windows Kits\10\Debuggers\x64\sym\fltMgr.pdb\A008BBBF87CC421FA0E568076A16F4BA2\fltMgr.pdb
DBGHELP: C:\Program Files (x86)\Windows Kits\10\Debuggers\x64\sym\fltMgr.pdb\A008BBBF87CC421FA0E568076A16F4BA2\fltMgr.pdb already cached
DBGHELP: C:\Program Files (x86)\Windows Kits\10\Debuggers\x64\sym\fltMgr.pdb\A008BBBF87CC421FA0E568076A16F4BA2\fltMgr.pdb already cached

DBGHELP: fltMgr - public symbols  
        C:\Program Files (x86)\Windows Kits\10\Debuggers\x64\sym\fltMgr.pdb\A008BBBF87CC421FA0E568076A16F4BA2\fltMgr.pdb

************* Symbol Loading Error Summary **************
Module name            Error
ntkrnlmp               The system cannot find the file specified
The SYMSRV client failed to find a file in the UNC store, or there
is an invalid UNC store (an invalid path or the pingme.txt file is
not present in the root directory), or the file is present in the
symbol server exclusion list.

0: kd> !analyze -show
FLTMGR_FILE_SYSTEM (f5)
An unrecoverable failure occured inside the filter manager.
Arguments:
Arg1: 000000000000006d, The reason for the failure
Arg2: fffffa8006b84af0
Arg3: fffffa8006b84a90
Arg4: 0000000000000000

(this bug check was generated by a driver that I have written to crash the system)

Answer 46

I think the best response for this would be that the symbol server is down, as I tested it on Windows 10 Pro x64 and it still throws me the same error.

SYMSRV:  BYINDEX: 0x44
         D:\Windows Kits\10\Debuggers\x64\sym
         gdi32full.pdb
         EDD3B562C327437EA507398DD6F37A671
SYMSRV:  D:\Windows Kits\10\Debuggers\x64\sym\gdi32full.pdb\EDD3B562C327437EA507398DD6F37A671\gdi32full.pdb - file not found
SYMSRV:  D:\Windows Kits\10\Debuggers\x64\sym\gdi32full.pdb\EDD3B562C327437EA507398DD6F37A671\gdi32full.pdb not found
SYMSRV:  BYINDEX: 0x45
         https://msdl.microsoft.com/download/symbols
         gdi32full.pdb
         EDD3B562C327437EA507398DD6F37A671
SYMSRV:  HTTPGET: /download/symbols/index2.txt

SYMSRV:  HttpQueryInfo: 502 - HTTP_STATUS_BAD_GATEWAY
SYMSRV:  HTTPGET: /download/symbols/gdi32full.pdb/EDD3B562C327437EA507398DD6F37A671/gdi32full.pdb

SYMSRV:  HttpQueryInfo: 502 - HTTP_STATUS_BAD_GATEWAY
SYMSRV:  D:\Windows Kits\10\Debuggers\x64\sym\gdi32full.pdb\EDD3B562C327437EA507398DD6F37A671\gdi32full.pdb - file not found
SYMSRV:  https://msdl.microsoft.com/download/symbols/gdi32full.pdb/EDD3B562C327437EA507398DD6F37A671/gdi32full.pdb not found
SYMSRV:  D:\Windows Kits\10\Debuggers\x64\sym\gdi32full.pdb\EDD3B562C327437EA507398DD6F37A671\gdi32full.pdb not found
DBGHELP: C:\WINDOWS\System32\gdi32full.pdb - file not found
DBGHELP: gdi32full.pdb - file not found
*** ERROR: Symbol file could not be found.  Defaulted to export symbols for C:\WINDOWS\System32\gdi32full.dll - 
DBGHELP: gdi32full - export symbols

Answer 47

I still see the same problem. Cannot download any Microsoft symbol for several days.

Answer 48

I have exactly the same problem today for clr.dll. 

0:000> .reload /f clr.dll
...
SYMSRV:  BYINDEX: 0x1E
         c:\symbols*https://msdl.microsoft.com/download/symbols
         clr.dll
         57E32896990000
SYMSRV:  c:\symbols\clr.dll\57E32896990000\clr.dll - file not found
SYMSRV:  HTTPGET: /download/symbols/clr.dll/57E32896990000/clr.dll
SYMSRV:  HttpQueryInfo: 502 - HTTP_STATUS_BAD_GATEWAY
SYMSRV:  c:\symbols\clr.dll\57E32896990000\clr.dll not found
SYMSRV:  https://msdl.microsoft.com/download/symbols/clr.dll/57E32896990000/clr.dll not found
DBGHELP: C:\Program Files (x86)\Windows Kits\10\Debuggers\clr.dll - file not found
DBGHELP: C:\Program Files (x86)\Windows Kits\10\Debuggers\clr.dll - file not found
DBGENG:  C:\Windows\Microsoft.NET\Framework64\v4.0.30319\clr.dll image header does not match memory image header.
DBGENG:  C:\Windows\Microsoft.NET\Framework64\v4.0.30319\clr.dll - Couldn't map image from disk.
Unable to load image C:\Windows\Microsoft.NET\Framework64\v4.0.30319\clr.dll, Win32 error 0n2
DBGHELP: No header for clr.dll.  Searching for dbg file
DBGHELP: .\clr.dbg - file not found
DBGHELP: .\dll\clr.dbg - path not found
DBGHELP: .\symbols\dll\clr.dbg - path not found
DBGHELP: clr.dll missing debug info.  Searching for pdb anyway
DBGHELP: Can't use symbol server for clr.pdb - no header information available
DBGHELP: Can't use symbol server for clr.pdb - no header information available
DBGHELP: Can't use symbol server for clr.pdb - no header information available
DBGHELP: clr.pdb - file not found
*** WARNING: Unable to verify timestamp for clr.dll
*** ERROR: Module load completed but symbols could not be loaded for clr.dll
DBGHELP: clr - no symbols loaded

If I try the URL http://msdl.microsoft.com/download/symbols/clr.dll/57E32896990000/clr.dll manually, I get HTTP 502 (Bad Gateway).

Answer 49

Apart from unreliable MS-symbol-server you have another problem:

DBGHELP: Can't use symbol server for clr.pdb - no header information available

You should retrieve matching module clr.dll first (e.g. from the box dump is taken from)  and point .exepath (do not forget .reload) to it.
Besides, somehow got the impression *.dll are more often missing than pdbs on symbol-server.

With kind regards

Answer 50

When I try to load the symbols am getting below error. Please check this.

0:007> .reload
Reloading current modules
............................................
*** ERROR: Symbol file could not be found.  Defaulted to export symbols for ntdll.dll - 


************* Symbol Loading Error Summary **************
Module name            Error
ntdll                  The system cannot find the file specified : srv*c:\symbols*https://msdl.microsoft.com/download/symbols

You can troubleshoot most symbol related issues by turning on symbol loading diagnostics (!sym noisy) and repeating the command that caused symbols to be loaded.
You should also verify that your symbol search path (.sympath) is correct.
0:007> !peb
PEB at 02b25000
*************************************************************************
***                                                                   ***
***                                                                   ***
***    Either you specified an unqualified symbol, or your debugger   ***
***    doesn't have full symbol information.  Unqualified symbol      ***
***    resolution is turned off by default. Please either specify a   ***
***    fully qualified symbol module!symbolname, or enable resolution ***
***    of unqualified symbols by typing ".symopt- 100". Note that   ***
***    enabling unqualified symbol resolution with network symbol     ***
***    server shares in the symbol path may cause the debugger to     ***
***    appear to hang for long periods of time when an incorrect      ***
***    symbol name is typed or the network symbol server is down.     ***
***                                                                   ***
***    For some commands to work properly, your symbol path           ***
***    must point to .pdb files that have full type information.      ***
***                                                                   ***
***    Certain .pdb files (such as the public OS symbols) do not      ***
***    contain the required information.  Contact the group that      ***
***    provided you with these symbols if you need this command to    ***
***    work.                                                          ***
***                                                                   ***
***    Type referenced: ntdll!_PEB                                    ***
***                                                                   ***
*************************************************************************
error 3 InitTypeRead( nt!_PEB at 02b25000).

My symbols are set to:

srv*c:\Symbols*https://msdl.microsoft.com/download/symbols

Answer 51

Apart from unreliable MS-symbol-server you have another problem:

DBGHELP: Can't use symbol server for clr.pdb - no header information available

You should retrieve matching module clr.dll first (e.g. from the box dump is taken from)  and point .exepath (do not forget .reload) to it.
Besides, somehow got the impression *.dll are more often missing than pdbs on symbol-server.

With kind regards

Really? I've done lots (looooooooots) of CLR debugging. I usually just need mscordacwks.dll and sos.dll from the customer's boxes, but it's new to me that I need clr.dll. Reading the log, it tries to download the clr.dll from the symbol server, but fails. I thought that was the root-problem here:

SYMSRV:  HTTPGET: /download/symbols/clr.dll/57E32896990000/clr.dll
SYMSRV:  HttpQueryInfo: 502 - HTTP_STATUS_BAD_GATEWAY

Answer 52

Ah yes, ms-symbol-server is unreliable, unreachable at times for me also . Accessing it (from Germany) :
Thursday (symchk) November 24, 2016
https://social.msdn.microsoft.com/Forums/vstudio/en-US/47d4125b-0a42-409b-a2e8-30bc1fed4090/stripped-pdb-files-for-net-framework-4xx-on-windows-7?forum=vsdebug

http://msdl.microsoft.com/download/symbols
and
http://referencesource.microsoft.com/symbols

Sunday  November 27, 2016
https://social.msdn.microsoft.com/Forums/vstudio/en-US/f89eb869-6f53-4a7a-8074-4e6214dda645/missing-symbol-for-ntdll-in-microsofts-symbol-server?forum=vsdebug#43d9c8c0-bbea-48ba-80b5-654f113c5160

needed some retries ...
(Just see, you do not have symbols for ntdll, so you are missing types for native debugger commands).

Clr.dll was meant more generally regarding modules. 
http://blogs.microsoft.co.il/sasha/2012/05/19/obtaining-mscordacwksdll-for-clr-versions-you-dont-have/
Suspect (personal opinion) windbg lately demands more modules - resembling Visual-Studio in this respect.
http://www.debuginfo.com/articles/matchmodules.html

With kind regards

Answer 53

I really need this server running again. My computer crashed and when I try to use the stack display, it is broken.

0: kd> k
 # Child-SP          RetAddr           Call Site
00 ffffe281`0122c208 fffff802`b9968629 nt+0x14a510
01 ffffe281`0122c210 00000000`00000139 nt+0x155629
02 ffffe281`0122c218 00000000`00000003 0x139
03 ffffe281`0122c220 ffffe281`0122c530 0x3
04 ffffe281`0122c228 ffffe281`0122c488 0xffffe281`0122c530
05 ffffe281`0122c230 00000000`00000000 0xffffe281`0122c488
0: kd> !analyze -show
KERNEL_SECURITY_CHECK_FAILURE (139)
A kernel component has corrupted a critical data structure.  The corruption
could potentially allow a malicious user to gain control of this machine.
Arguments:
Arg1: 0000000000000003, A LIST_ENTRY has been corrupted (i.e. double remove).
Arg2: ffffe2810122c530, Address of the trap frame for the exception that caused the bugcheck
Arg3: ffffe2810122c488, Address of the exception record for the exception that caused the bugcheck
Arg4: 0000000000000000, Reserved
0: kd> .trap ffffe2810122c530
NOTE: The trap frame does not contain all registers.
Some register values may be zeroed or incorrect.
rax=ffffc18088727820 rbx=0000000000000000 rcx=0000000000000003
rdx=ffffc18088728820 rsi=0000000000000000 rdi=0000000000000000
rip=fffff802b9a617cd rsp=ffffe2810122c6c0 rbp=fffff802b9b4d680
 r8=ffffe2810122c740  r9=c6d1e582befb4fd1 r10=ffff9b8000000c20
r11=0000000000000001 r12=0000000000000000 r13=0000000000000000
r14=0000000000000000 r15=0000000000000000
iopl=0         nv up ei pl nz na po cy
nt+0x24e7cd:
fffff802`b9a617cd cd29            int     29h
0: kd> k
  *** Stack trace for last set context - .thread/.cxr resets it
 # Child-SP          RetAddr           Call Site
00 ffffe281`0122c6c0 ffffc180`8c057080 nt+0x24e7cd
01 ffffe281`0122c6c8 fffff802`b9b4e7c0 0xffffc180`8c057080
02 ffffe281`0122c6d0 00000000`00000081 nt+0x33b7c0
03 ffffe281`0122c6d8 fffff802`b9813000 0x81
04 ffffe281`0122c6e0 00000000`00000001 nt
SYMSRV:  BYINDEX: 0x32A
         D:\Windows Kits\10\Debuggers\x64\sym
         win32kbase.sys
         5819BCA2180000
SYMSRV:  D:\Windows Kits\10\Debuggers\x64\sym\win32kbase.sys\5819BCA2180000\win32kbase.sys - file not found
SYMSRV:  D:\Windows Kits\10\Debuggers\x64\sym\win32kbase.sys\5819BCA2180000\win32kbase.sys not found
SYMSRV:  BYINDEX: 0x32B
         https://msdl.microsoft.com/download/symbols
         win32kbase.sys
         5819BCA2180000
SYMSRV:  HTTPGET: /download/symbols/win32kbase.sys/5819BCA2180000/win32kbase.sys
SYMSRV:  HttpQueryInfo: 502 - HTTP_STATUS_BAD_GATEWAY
SYMSRV:  D:\Windows Kits\10\Debuggers\x64\sym\win32kbase.sys\5819BCA2180000\win32kbase.sys - file not found
SYMSRV:  https://msdl.microsoft.com/download/symbols/win32kbase.sys/5819BCA2180000/win32kbase.sys not found
SYMSRV:  D:\Windows Kits\10\Debuggers\x64\sym\win32kbase.sys\5819BCA2180000\win32kbase.sys not found
DBGHELP: D:\Windows Kits\10\Debuggers\x64\win32kbase.sys - file not found
DBGHELP: D:\Windows Kits\10\Debuggers\x64\win32kbase.sys - file not found
SYMSRV:  BYINDEX: 0x32C
         https://msdl.microsoft.com/download/symbols
         win32kbase.sys
         5819BCA2180000
SYMSRV:  HTTPGET: /download/symbols/win32kbase.sys/5819BCA2180000/win32kbase.sys
SYMSRV:  HttpQueryInfo: 502 - HTTP_STATUS_BAD_GATEWAY
SYMSRV:  D:\Windows Kits\10\Debuggers\x64\sym\win32kbase.sys\5819BCA2180000\win32kbase.sys - file not found
SYMSRV:  https://msdl.microsoft.com/download/symbols/win32kbase.sys/5819BCA2180000/win32kbase.sys not found
SYMSRV:  D:\Windows Kits\10\Debuggers\x64\sym\win32kbase.sys\5819BCA2180000\win32kbase.sys not found
DBGENG:  \SystemRoot\System32\win32kbase.sys - Image mapping disallowed by non-local path.
DBGENG:  win32kbase.sys - Partial symbol image load missing image info
DBGHELP: No header for win32kbase.sys.  Searching for dbg file
DBGHELP: .\win32kbase.dbg - file not found
DBGHELP: .\sys\win32kbase.dbg - path not found
DBGHELP: .\symbols\sys\win32kbase.dbg - path not found
DBGHELP: win32kbase.sys missing debug info.  Searching for pdb anyway
DBGHELP: Can't use symbol server for win32kbase.pdb - no header information available
DBGHELP: win32kbase.pdb - file not found
*** WARNING: Unable to verify timestamp for win32kbase.sys
*** ERROR: Module load completed but symbols could not be loaded for win32kbase.sys
DBGHELP: win32kbase - no symbols loaded
05 ffffe281`0122c6e8 ffff93b5`fd9eea92 0x1
06 ffffe281`0122c6f0 00000000`00000000 win32kbase+0x5ea92

Only symbols that are cached on my system will work (the only ones I have for Windows 10 x64 1607 are fltMgr.sys and fileinfo.sys) and loading these does not help the stack display any better.

Answer 54

I have no problem reaching the server (from Germany). My problem is that many Windows symbol files are still missing. I'm trying to debug a scenario for more than two weeks now, but without many MSFT symbols, it's almost impossible.

---

Armin

Answer 55

I do also have this Issue.

For example: https://msdl.microsoft.com/download/symbols/wkernel32.pdb/AB6B617AB7E1496AB63555DEBF8A91B12/wkernel32.pdb

Answer 56

Same for me! I am not able to download any symbols needed for kernel mode debugging since days. This effectifly stops my working. The only workaround for me is to install a new fresh installation without any updates and to install a full instalallation of the downloaded symbols.

I have created a connect feedback! Please vote:

https://connect.microsoft.com/VisualStudio/feedback/details/3113570/https-msdl-microsoft-com-download-symbols-symbol-server-is-down-since-days

Regdards,

Thomas.

Answer 57

There's a few (new) different issues here on a fairly old thread, so in the future please make new threads when you hit issues.

On the topic of symbols missing (404s) there are currently a few recent releases/KBs that do not have their symbols available on the symbol server. We're aware of the issue and working on making them available.

On the topic of 502s, we just started redirecting some of the traffic to Microsoft's symbol server to a caching back-end in Azure in an effort to get faster and more reliable. We saw some people hitting some 502 errors earlier as part of this move and we believe they're fixed now. If you see anything out of the ordinary when debugging with the symbol server, please reach to [e-mail] with the noisy symbol output and version of your target.

On the topic of general slowness, see above, we're working on enabling caching in Azure to improve the reliability and performance.