Application hang being caused by StackPanel?

Question

I've been following the instructions in http://blogs.msdn.com/b/windowsstore/archive/2012/06/27/improving-apps-with-quality-reports.aspx to try and understand what is causing the failures being reported on my app's dashboard.

One of the application hangs *appears* to be being caused by StackPanel. The stack text displayed in WinDbg is:

STACK_TEXT:  
0000009e`3b80efc8 000007fb`051bf1f8 : 0000009e`3c35c420 0000009e`3b80f350 0000009e`1fae88d0 0000009e`1fae88d0 : Windows_UI_Xaml!DirectUI::StackPanel::~StackPanel
0000009e`3b80efd0 000007fb`04c883ae : aaaaaaaa`aaaaaaaa aaaaaaaa`aaaaaaaa 0000009e`3c35c468 000007fb`04c8804a : Windows_UI_Xaml!ctl::ComObject<DirectUI::StackPanel>::`scalar deleting destructor'+0x14
0000009e`3b80f000 000007fb`0503229b : 00000000`00000000 0000009e`3dde5880 00000000`00000000 aaaaaaaa`aaaaaaaa : Windows_UI_Xaml!DirectUI::DependencyObject::OnFinalRelease+0x7f
0000009e`3b80f030 000007fb`04c87dad : 0000009e`3b80f0c0 000007fb`051b96a0 aaaaaaaa`aaaaaaaa aaaaaaaa`aaaaaaaa : Windows_UI_Xaml!ctl::AggregableComObject<DirectUI::TextBox>::NonDelegatingRelease+0x37
0000009e`3b80f060 000007fb`04c88b22 : 0000009e`3f4c38a0 000007fb`04c883ae aaaaaaaa`aaaaaaaa aaaaaaaa`aaaaaaaa : Windows_UI_Xaml!ctl::release_interface<DirectUI::DependencyObject>+0x29
0000009e`3b80f090 000007fb`04d3c14b : 0000009e`3c35c468 aaaaaaaa`aaaaaaaa 0000009e`3dde5880 aaaaaaaa`aaaaaaaa : Windows_UI_Xaml!DirectUI::DependencyObject::ReleaseForPeerReferenceHelper+0x7b
0000009e`3b80f0c0 000007fb`052d3c88 : 00000000`00000000 aaaaaaaa`aaaaaaaa aaaaaaaa`aaaaaaaa 0000009e`3b80f350 : Windows_UI_Xaml!DirectUI::DependencyObject::ClearPeerReferences+0x181
0000009e`3b80f100 000007fb`05039b21 : aaaaaaaa`aaaaaaaa aaaaaaaa`aaaaaaaa 00000000`00000000 00000000`00000000 : Windows_UI_Xaml!DirectUI::DependencyObject::Deinitialize+0x34
0000009e`3b80f130 000007fb`04c76f75 : 0000009e`3dde5888 00000000`00000344 0000009e`3c345850 0000009e`1fae88d0 : Windows_UI_Xaml!DirectUI::UIAffinityReleaseQueue::Cleanup+0x13f
0000009e`3b80f1a0 000007fb`04c76c51 : 0000009e`1fae88d0 0000009e`3b80f350 00000000`00000000 0000009e`1faed720 : Windows_UI_Xaml!AgCoreCallbacks::PerFrameCallback+0x3d
0000009e`3b80f1d0 000007fb`04c75d57 : 00000000`00000000 0000009e`3b80f350 00000000`00000000 aaaaaaaa`aaaaaaaa : Windows_UI_Xaml!CCoreServices::Tick+0x1a1
0000009e`3b80f250 000007fb`04c75a60 : aaaaaaaa`aaaaaaaa aaaaaaaa`aaaaaaaa 00000000`00000000 00000000`00000000 : Windows_UI_Xaml!CCoreServices::NWDrawTree+0x297
0000009e`3b80f4a0 000007fb`04c75136 : 0000009e`1fae7500 00000000`00000000 00000000`00000000 0000009e`3b80f570 : Windows_UI_Xaml!CWindowRenderTarget::Draw+0x3c6
0000009e`3b80f550 000007fb`04c74f21 : 0000009e`1fad4c50 0000009e`1faed720 0000009e`1fad4c50 00000000`00000000 : Windows_UI_Xaml!CXcpBrowserHost::OnTick+0x1e6
0000009e`3b80f5a0 000007fb`04c76a8b : 00000000`00000000 aaaaaaaa`aaaaaaaa aaaaaaaa`aaaaaaaa aaaaaaaa`aaaaaaaa : Windows_UI_Xaml!CXcpDispatcher::Tick+0xf1
0000009e`3b80f5f0 000007fb`04c72c54 : aaaaaaaa`aaaaaaaa 00000000`00000000 0000009e`1fad4c50 aaaaaaaa`aaaaaaaa : Windows_UI_Xaml!CXcpDispatcher::OnReentrancyProtectedWindowMessage+0x47
0000009e`3b80f630 000007fb`3339171e : aaaaaaaa`aaaaaaaa 0000009e`3b80f820 aaaaaaaa`aaaaaaaa 000007fb`26f0a156 : Windows_UI_Xaml!CXcpDispatcher::WindowProc+0xa0
0000009e`3b80f680 000007fb`333914d7 : aaaaaaaa`aaaaaaaa 0000009e`3b80f7f0 000007f5`ffbce800 000007fb`04c72bb0 : user32!UserCallWinProcCheckWow+0x13a
0000009e`3b80f740 000007fb`1e7c10c7 : aaaaaaaa`aaaaaaaa aaaaaaaa`aaaaaaaa aaaaaaaa`aaaaaaaa 000007fb`3323bd30 : user32!DispatchMessageWorker+0x1a7
0000009e`3b80f7c0 000007fb`1e7c11a4 : aaaaaaaa`aaaaaaaa aaaaaaaa`aaaaaaaa 00000000`00000000 0000009e`3c856ee0 : windows_ui!Windows::UI::Core::CDispatcher::ProcessMessage+0xe2
0000009e`3b80f840 000007fb`04cd7f84 : 00000000`00000000 00000000`00000000 00000000`00000000 0000009e`3b80fa40 : windows_ui!Windows::UI::Core::CDispatcher::ProcessEvents+0x9a
0000009e`3b80f900 000007fb`04cd7f37 : 0000009e`3c856ee0 000007fb`3323c1e1 0000009e`3c8545d0 0000009e`3c8545c0 : Windows_UI_Xaml!CJupiterWindow::RunCoreWindowMessageLoop+0x3c
0000009e`3b80f930 000007fb`04d3e646 : 0000009e`1fae88d0 aaaaaaaa`aaaaaaaa 00000000`00000000 000007fb`33219b62 : Windows_UI_Xaml!CJupiterControl::RunMessageLoop+0x27
0000009e`3b80f990 000007fb`26e917ac : 00000000`00000000 0000009e`1f54c6b0 000007fb`26f15170 00000000`00000000 : Windows_UI_Xaml!DirectUI::DXamlCore::RunMessageLoop+0x33
0000009e`3b80f9c0 000007fb`26e918be : 0000009e`1f95e740 aaaaaaaa`aaaaaaaa 00000000`00000000 00000000`00000000 : twinapi!Windows::ApplicationModel::Core::CoreApplicationView::Run+0x30
0000009e`3b80f9f0 000007fb`302040bc : 00000000`00000000 0000009e`1f5490f0 0000009e`1f54c090 0000009e`1f95e740 : twinapi!Microsoft::WRL::Details::CreateActivationFactory<Windows::ApplicationModel::Core::CoreApplicationFactory>+0x35e
0000009e`3b80fa40 000007fb`326b1832 : 00000000`00000000 00000000`00000000 00000000`00000000 00000000`00000000 : SHCore!COplockFileHandle::v_GetHandlerCLSID+0x12c
0000009e`3b80fb30 000007fb`34e8d609 : 00000000`00000000 00000000`00000000 00000000`00000000 00000000`00000000 : kernel32!BaseThreadInitThunk+0x1a
0000009e`3b80fb60 00000000`00000000 : 00000000`00000000 00000000`00000000 00000000`00000000 00000000`00000000 : ntdll!RtlUserThreadStart+0x1d

I cannot see any part of my app on this stack trace, so I'm unclear as to what steps I might be able to take to prevent this from happening. I can't even figure out *where* in my app this is taking place.

Any suggestions as to either how I can interrogate the dump further or steps I can take in my app to prevent this?

Thanks.

Philip

 

Answer 1

Do the other threads show any activity?

---

Matt Small - Microsoft Escalation Engineer - Forum Moderator
If my reply answers your question, please mark this post as answered.

NOTE: If I ask for code, please provide something that I can drop directly into a project and run (including XAML), or an actual application project. I'm trying to help a lot of people, so I don't have time to figure out weird snippets with undefined objects and unknown namespaces.

Answer 2

Do the other threads show any activity?

---

 

What I've pasted seemed to be the most relevant bit from the crash dump. I'm not that familiar with how to use WinDbg so I may be overlooking something, but it should be noted that this is from a downloaded crash dump and not from a running instance of my app.

Answer 3

In case I have missed out anything vital by just showing the stack text, here is the full analysis of the exception:

0:006> !analyze -v
*******************************************************************************
*                                                                             *
*                        Exception Analysis                                   *
*                                                                             *
*******************************************************************************

Unable to load image mscorlib.ni.dll, Win32 error 0n2
*** WARNING: Unable to verify checksum for mscorlib.ni.dll
Unable to load image Windows.UI.Xaml.ni.dll, Win32 error 0n2
*** WARNING: Unable to verify checksum for Windows.UI.Xaml.ni.dll
*** ERROR: Module load completed but symbols could not be loaded for Windows.UI.Xaml.ni.dll
Unable to load image Relative History.ni.exe, Win32 error 0n2
*** WARNING: Unable to verify checksum for Relative History.ni.exe
*** ERROR: Module load completed but symbols could not be loaded for Relative History.ni.exe
*** WARNING: Unable to verify timestamp for sqlite3.dll
*** ERROR: Module load completed but symbols could not be loaded for sqlite3.dll

FAULTING_IP: 
+0
00000000`00000000 ??              ???

EXCEPTION_RECORD:  ffffffffffffffff -- (.exr 0xffffffffffffffff)
ExceptionAddress: 0000000000000000
   ExceptionCode: cfffffff (Application hang)
  ExceptionFlags: 00000001
NumberParameters: 0

BUGCHECK_STR:  HANG

DEFAULT_BUCKET_ID:  APPLICATION_HANG

PROCESS_NAME:  Relative History.exe

ORIGINAL_CAB_PATH:  C:\Users\Philip\Desktop\524509e3-b8db-4456-8f89-0f96567734f3_Hang_12462276.cab

ERROR_CODE: (NTSTATUS) 0xcfffffff - <Unable to get error code text>

EXCEPTION_CODE: (NTSTATUS) 0xcfffffff - <Unable to get error code text>

NTGLOBALFLAG:  0

APP:  relative history.exe

MANAGED_STACK: !dumpstack -EE
OS Thread Id: 0x8fac (6)
Current frame: 
Child-SP         RetAddr          Caller, Callee

DERIVED_WAIT_CHAIN:  

Dl Eid Cid     WaitType
-- --- ------- --------------------------
   6   aafc.8fac Unknown                

WAIT_CHAIN_COMMAND:  ~6s;k;;

BLOCKING_THREAD:  0000000000008fac

PRIMARY_PROBLEM_CLASS:  APPLICATION_HANG

LAST_CONTROL_TRANSFER:  from 000007fb051bf1f8 to 000007fb05399a80

FAULTING_THREAD:  0000000000000006

STACK_TEXT:  
0000009e`3b80efc8 000007fb`051bf1f8 : 0000009e`3c35c420 0000009e`3b80f350 0000009e`1fae88d0 0000009e`1fae88d0 : Windows_UI_Xaml!DirectUI::StackPanel::~StackPanel
0000009e`3b80efd0 000007fb`04c883ae : aaaaaaaa`aaaaaaaa aaaaaaaa`aaaaaaaa 0000009e`3c35c468 000007fb`04c8804a : Windows_UI_Xaml!ctl::ComObject<DirectUI::StackPanel>::`scalar deleting destructor'+0x14
0000009e`3b80f000 000007fb`0503229b : 00000000`00000000 0000009e`3dde5880 00000000`00000000 aaaaaaaa`aaaaaaaa : Windows_UI_Xaml!DirectUI::DependencyObject::OnFinalRelease+0x7f
0000009e`3b80f030 000007fb`04c87dad : 0000009e`3b80f0c0 000007fb`051b96a0 aaaaaaaa`aaaaaaaa aaaaaaaa`aaaaaaaa : Windows_UI_Xaml!ctl::AggregableComObject<DirectUI::TextBox>::NonDelegatingRelease+0x37
0000009e`3b80f060 000007fb`04c88b22 : 0000009e`3f4c38a0 000007fb`04c883ae aaaaaaaa`aaaaaaaa aaaaaaaa`aaaaaaaa : Windows_UI_Xaml!ctl::release_interface<DirectUI::DependencyObject>+0x29
0000009e`3b80f090 000007fb`04d3c14b : 0000009e`3c35c468 aaaaaaaa`aaaaaaaa 0000009e`3dde5880 aaaaaaaa`aaaaaaaa : Windows_UI_Xaml!DirectUI::DependencyObject::ReleaseForPeerReferenceHelper+0x7b
0000009e`3b80f0c0 000007fb`052d3c88 : 00000000`00000000 aaaaaaaa`aaaaaaaa aaaaaaaa`aaaaaaaa 0000009e`3b80f350 : Windows_UI_Xaml!DirectUI::DependencyObject::ClearPeerReferences+0x181
0000009e`3b80f100 000007fb`05039b21 : aaaaaaaa`aaaaaaaa aaaaaaaa`aaaaaaaa 00000000`00000000 00000000`00000000 : Windows_UI_Xaml!DirectUI::DependencyObject::Deinitialize+0x34
0000009e`3b80f130 000007fb`04c76f75 : 0000009e`3dde5888 00000000`00000344 0000009e`3c345850 0000009e`1fae88d0 : Windows_UI_Xaml!DirectUI::UIAffinityReleaseQueue::Cleanup+0x13f
0000009e`3b80f1a0 000007fb`04c76c51 : 0000009e`1fae88d0 0000009e`3b80f350 00000000`00000000 0000009e`1faed720 : Windows_UI_Xaml!AgCoreCallbacks::PerFrameCallback+0x3d
0000009e`3b80f1d0 000007fb`04c75d57 : 00000000`00000000 0000009e`3b80f350 00000000`00000000 aaaaaaaa`aaaaaaaa : Windows_UI_Xaml!CCoreServices::Tick+0x1a1
0000009e`3b80f250 000007fb`04c75a60 : aaaaaaaa`aaaaaaaa aaaaaaaa`aaaaaaaa 00000000`00000000 00000000`00000000 : Windows_UI_Xaml!CCoreServices::NWDrawTree+0x297
0000009e`3b80f4a0 000007fb`04c75136 : 0000009e`1fae7500 00000000`00000000 00000000`00000000 0000009e`3b80f570 : Windows_UI_Xaml!CWindowRenderTarget::Draw+0x3c6
0000009e`3b80f550 000007fb`04c74f21 : 0000009e`1fad4c50 0000009e`1faed720 0000009e`1fad4c50 00000000`00000000 : Windows_UI_Xaml!CXcpBrowserHost::OnTick+0x1e6
0000009e`3b80f5a0 000007fb`04c76a8b : 00000000`00000000 aaaaaaaa`aaaaaaaa aaaaaaaa`aaaaaaaa aaaaaaaa`aaaaaaaa : Windows_UI_Xaml!CXcpDispatcher::Tick+0xf1
0000009e`3b80f5f0 000007fb`04c72c54 : aaaaaaaa`aaaaaaaa 00000000`00000000 0000009e`1fad4c50 aaaaaaaa`aaaaaaaa : Windows_UI_Xaml!CXcpDispatcher::OnReentrancyProtectedWindowMessage+0x47
0000009e`3b80f630 000007fb`3339171e : aaaaaaaa`aaaaaaaa 0000009e`3b80f820 aaaaaaaa`aaaaaaaa 000007fb`26f0a156 : Windows_UI_Xaml!CXcpDispatcher::WindowProc+0xa0
0000009e`3b80f680 000007fb`333914d7 : aaaaaaaa`aaaaaaaa 0000009e`3b80f7f0 000007f5`ffbce800 000007fb`04c72bb0 : user32!UserCallWinProcCheckWow+0x13a
0000009e`3b80f740 000007fb`1e7c10c7 : aaaaaaaa`aaaaaaaa aaaaaaaa`aaaaaaaa aaaaaaaa`aaaaaaaa 000007fb`3323bd30 : user32!DispatchMessageWorker+0x1a7
0000009e`3b80f7c0 000007fb`1e7c11a4 : aaaaaaaa`aaaaaaaa aaaaaaaa`aaaaaaaa 00000000`00000000 0000009e`3c856ee0 : windows_ui!Windows::UI::Core::CDispatcher::ProcessMessage+0xe2
0000009e`3b80f840 000007fb`04cd7f84 : 00000000`00000000 00000000`00000000 00000000`00000000 0000009e`3b80fa40 : windows_ui!Windows::UI::Core::CDispatcher::ProcessEvents+0x9a
0000009e`3b80f900 000007fb`04cd7f37 : 0000009e`3c856ee0 000007fb`3323c1e1 0000009e`3c8545d0 0000009e`3c8545c0 : Windows_UI_Xaml!CJupiterWindow::RunCoreWindowMessageLoop+0x3c
0000009e`3b80f930 000007fb`04d3e646 : 0000009e`1fae88d0 aaaaaaaa`aaaaaaaa 00000000`00000000 000007fb`33219b62 : Windows_UI_Xaml!CJupiterControl::RunMessageLoop+0x27
0000009e`3b80f990 000007fb`26e917ac : 00000000`00000000 0000009e`1f54c6b0 000007fb`26f15170 00000000`00000000 : Windows_UI_Xaml!DirectUI::DXamlCore::RunMessageLoop+0x33
0000009e`3b80f9c0 000007fb`26e918be : 0000009e`1f95e740 aaaaaaaa`aaaaaaaa 00000000`00000000 00000000`00000000 : twinapi!Windows::ApplicationModel::Core::CoreApplicationView::Run+0x30
0000009e`3b80f9f0 000007fb`302040bc : 00000000`00000000 0000009e`1f5490f0 0000009e`1f54c090 0000009e`1f95e740 : twinapi!Microsoft::WRL::Details::CreateActivationFactory<Windows::ApplicationModel::Core::CoreApplicationFactory>+0x35e
0000009e`3b80fa40 000007fb`326b1832 : 00000000`00000000 00000000`00000000 00000000`00000000 00000000`00000000 : SHCore!COplockFileHandle::v_GetHandlerCLSID+0x12c
0000009e`3b80fb30 000007fb`34e8d609 : 00000000`00000000 00000000`00000000 00000000`00000000 00000000`00000000 : kernel32!BaseThreadInitThunk+0x1a
0000009e`3b80fb60 00000000`00000000 : 00000000`00000000 00000000`00000000 00000000`00000000 00000000`00000000 : ntdll!RtlUserThreadStart+0x1d


FOLLOWUP_IP: 
Windows_UI_Xaml!DirectUI::StackPanel::~StackPanel+0 [d:\win8_gdr\windows\dxaml\xcp\dxaml\lib\stackpanel_partial.cpp @ 22]
000007fb`05399a80 488d05c943bbff  lea     rax,[Windows_UI_Xaml!DirectUI::StackPanel::`vftable' (000007fb`04f4de50)]

FAULTING_SOURCE_LINE:  d:\win8_gdr\windows\dxaml\xcp\dxaml\lib\stackpanel_partial.cpp

FAULTING_SOURCE_FILE:  d:\win8_gdr\windows\dxaml\xcp\dxaml\lib\stackpanel_partial.cpp

FAULTING_SOURCE_LINE_NUMBER:  22

SYMBOL_STACK_INDEX:  0

SYMBOL_NAME:  windows_ui_xaml!DirectUI::StackPanel::~StackPanel+9e3b80efc0

FOLLOWUP_NAME:  MachineOwner

MODULE_NAME: Windows_UI_Xaml

IMAGE_NAME:  Windows.UI.Xaml.ni.dll

DEBUG_FLR_IMAGE_TIMESTAMP:  51847e24

STACK_COMMAND:  ~6s ; kb

BUCKET_ID:  HANG_windows_ui_xaml!DirectUI::StackPanel::_StackPanel+9e3b80efc0

FAILURE_BUCKET_ID:  APPLICATION_HANG_cfffffff_Windows.UI.Xaml.ni.dll!DirectUI::StackPanel::_StackPanel

Followup: MachineOwner
---------

Answer 4

Please post a link to the dump.

Also, run !locks

---

Matt Small - Microsoft Escalation Engineer - Forum Moderator
If my reply answers your question, please mark this post as answered.

NOTE: If I ask for code, please provide something that I can drop directly into a project and run (including XAML), or an actual application project. I'm trying to help a lot of people, so I don't have time to figure out weird snippets with undefined objects and unknown namespaces.

Answer 5

Link to the dump: http://sdrv.ms/U8Su3U

Running !locks:

0:006> !locks
NTSDEXTS: Unable to read memory at ntdll!RtlCriticalSectionList

Thanks for your help.

Philip

Answer 6

My gut feeling is that thread 16 is your problem:

0:016> knL
 # Child-SP          RetAddr           Call Site
00 0000009e`3c80e7a8 000007fb`320d84cf ntdll!ZwReadFile+0xa
01 0000009e`3c80e7b0 000007fb`03a9b752 KERNELBASE!ReadFile+0x11b
02 0000009e`3c80e830 aaaaaaaa`aaaaaaaa sqlite3+0xb752
03 0000009e`3c80e838 0000009e`3f4f0f88 0xaaaaaaaa`aaaaaaaa
04 0000009e`3c80e840 00000000`00000000 0x0000009e`3f4f0f88

I can't tell what's going on here other than SQLite is writing something to a file, most likely the database file.

---

Matt Small - Microsoft Escalation Engineer - Forum Moderator
If my reply answers your question, please mark this post as answered.

NOTE: If I ask for code, please provide something that I can drop directly into a project and run (including XAML), or an actual application project. I'm trying to help a lot of people, so I don't have time to figure out weird snippets with undefined objects and unknown namespaces.

Answer 7

Hi Matt

For my education, how are you determining that it is thread 16?

I find it somewhat interesting that there are no references to my own code, which means it is difficult for me to figure out what calls I might be making.

The SQLite code is the distributed version. Presumably if I want to get more information out of future crash dumps, I need to get the source code itself for SQLite and then include binary code that I've built myself so that I can then point the debugger at my symbols?

If I hover over the Failure name on the Dashboard (which for some reason is truncated with no easy way to get the full name) then I can see it is "APPLICATION_HANG_ACTIVATION_BlockedOn_FileIO_cfffffff_sqlite_open_v2".

The app is suffering from a second failure where suspend is taking too long :-(. The crash dump for that one can be found here: http://sdrv.ms/U8Su3U. Again, I cannot find any reference to my own code so I'm struggling to figure out what I can do to fix this problem either.

Answer 8

I don't have confirmation on that - the dump lacks enough information for me to really know the exact position of the hang.  However, knowing that a hang process sits for a long time, and that presumably, everything else that takes place should have already happened by the time that the dump is captured, I can't think of a reason why SQLLite would be reading from the database at the time of the hang, unless it was actually hung right there.

The callstack for the StackPanel doesn't seem to indicate a hang at all, and it doesn't seem to be doing anything.  A ReadFile will actually use I/O, so I know it's a relatively slow process.

And now looking at your post again, I see that the failure name points straight at SQLite...

I'll look at the second dump for a confirmation.

---

Matt Small - Microsoft Escalation Engineer - Forum Moderator
If my reply answers your question, please mark this post as answered.

NOTE: If I ask for code, please provide something that I can drop directly into a project and run (including XAML), or an actual application project. I'm trying to help a lot of people, so I don't have time to figure out weird snippets with undefined objects and unknown namespaces.

Answer 9

I did not get confirmation on what's causing the hang in the second dump.  I am not convinced it's the same issue.

---

Matt Small - Microsoft Escalation Engineer - Forum Moderator
If my reply answers your question, please mark this post as answered.

NOTE: If I ask for code, please provide something that I can drop directly into a project and run (including XAML), or an actual application project. I'm trying to help a lot of people, so I don't have time to figure out weird snippets with undefined objects and unknown namespaces.

Answer 10

Hi Matt

Thank you for looking into this.

Is there anything I can do, either in the build process or in my code, that can assist either with troubleshooting this further or (better still) stopping this from happening?

I'm still unsure why I'm not seeing any references to my own code in either dump. It suggests that the problem is occurring outside of my code's execution?

Regards

Philip

Answer 11

Phillip - if order to take this to the next level, you can open a support case and we'll have some debug experts look at it.

---

Matt Small - Microsoft Escalation Engineer - Forum Moderator
If my reply answers your question, please mark this post as answered.

NOTE: If I ask for code, please provide something that I can drop directly into a project and run (including XAML), or an actual application project. I'm trying to help a lot of people, so I don't have time to figure out weird snippets with undefined objects and unknown namespaces.