locked
Unable to copy from obj\debug to bin\debug

    Question

  • I get the following error when I try to run my program.

     Error 1 Unable to copy file "obj\Debug\HomeInventory.exe" to "bin\Debug\HomeInventory.exe". The process cannot access the file 'bin\Debug\HomeInventory.exe' because it is being used by another process. HomeInventory

    Saturday, January 14, 2006 1:06 AM

Answers

  • OK, I've found out how to sort it out. I ran a program which figured out which application had the file locked, and it turned out to be devenv.exe, i.e. Visual Studio itself. A bit more searching and I found a fix.

    Create a pre-build action in your project by going to project properties (right-click on the project in the solution explorer, and select the Properties option), select the Build Events tab. Add this code:

    if exist "$(TargetPath).locked" del "$(TargetPath).locked"
    if not exist "$(TargetPath).locked" move "$(TargetPath)" "$(TargetPath).locked"

    This copies the file to a different name, and allows the build to continue successfully.

    Hope that helps anyone else who's got this problem.

    Matthew

    Tuesday, April 11, 2006 9:34 AM

All replies

  • I get this same error when I'm trying to build a class library which contains custom controls. It seems that visual studio has it locked: I can restart visual studio, or switch to a different project and back again, and I can build the library successfully, once. I can then run the app in debug, but if I make changes and try to run it again I'm back to getting the 'Unable to copy file...' error. It must be something to do with the particular library, as I have other libraries with custom controls in them which work fine.

    Any help would be greatly appreciated as this is really slowing down my development.

    Matthew

    Monday, April 10, 2006 11:03 AM
  • OK, I've found out how to sort it out. I ran a program which figured out which application had the file locked, and it turned out to be devenv.exe, i.e. Visual Studio itself. A bit more searching and I found a fix.

    Create a pre-build action in your project by going to project properties (right-click on the project in the solution explorer, and select the Properties option), select the Build Events tab. Add this code:

    if exist "$(TargetPath).locked" del "$(TargetPath).locked"
    if not exist "$(TargetPath).locked" move "$(TargetPath)" "$(TargetPath).locked"

    This copies the file to a different name, and allows the build to continue successfully.

    Hope that helps anyone else who's got this problem.

    Matthew

    Tuesday, April 11, 2006 9:34 AM
  • Hi,

    I had the same problem after converting a VS2005 WebSite to Web Application Project. It has been a pain everytime i need to compile.

    The above code solved the problem. Thanks!

    Ricardo

    Tuesday, March 13, 2007 10:13 AM
  • This has solved my greatest pain in last few days. Thanks.

     

    But one small improvement is neccessary to let the hack work also if the build is run from scratch, e.g. after clean:

    if exist "$(TargetPath).locked" del "$(TargetPath).locked"
     if not exist "$(TargetPath).locked" if exist "$(TargetPath)" move "$(TargetPath)" "$(TargetPath).locked"

     

     

    It works for me. I hope it would work for anybody else who will need it.

     

    Petr

    Monday, May 14, 2007 7:10 AM
  • The supplied pre-build code works for me, once. But after the one successful build, VS is back to throwing errors at me again.

    Is there some reason as to why the pre-build commands won't run properly every time?
    Tuesday, May 15, 2007 10:09 AM
  • The first reason I can imagine is some lock on the file. I've believed that this should be definitely solved by my patch, but maybe I am wrong in some way. I would suggest you to study content of the "Output" window in VS and try to figure out what goes wrong. If you find the error, you can post it.
    Monday, May 28, 2007 6:56 AM
  • Look for the  Project.exe and Project.exe.vshost etc in the TaskManager and clear them off.

    Then try to build/ Run the projectSee if that helps.

     

    Thanks

    Seshu

     

    Tuesday, February 05, 2008 3:53 PM
  •  

    Thanks Petr.

     

    works for me as well !!

     

     

    Thursday, February 07, 2008 1:09 AM
  • Did anyone actually check to see if the file in question was actually locked.  I had a very similar problem and found that my .dll and .pdb files had somehow been checked into Visual Source Safe (VSS), which in fact had locked both files.  I did have to manually delete them from the bin directory which also asked if I wanted to delete them from VSS, and I of course replied "YES".

     

     

    • Proposed as answer by Allastanao Wednesday, December 17, 2008 7:56 AM
    Tuesday, March 04, 2008 6:51 PM
  •  

    This solution looks well and good, but for visual studio to be locking your own dll files. It sounds like a bug in project references.

     

    anyone submit this one?

    • Proposed as answer by Allastanao Wednesday, December 17, 2008 7:56 AM
    Tuesday, November 25, 2008 8:38 PM
  • I had a similar problem and I solved it excluding from the project in VSS (Visual Source Safe) the folders bin and obj. Then all worked.
    Wednesday, December 17, 2008 7:58 AM
  •  
    Bruno said as I did and it worked!
    But someone knows why this happens?
    Thursday, January 15, 2009 11:18 AM
  • An easier way is to manually delete the "obj" folder and rebuild the project. This usually works for me.
    Thursday, January 14, 2010 11:08 AM
  • I also thought so, but everytime you build it, it throws the same error and everytime you need to delete the obj folder which is not a good solution. I am still looking for a viable one.
    Monday, May 24, 2010 4:00 PM
  • The solution proposed by "Peaches June" solved my problem.
    Monday, May 24, 2010 4:04 PM
  • I have the exact same problem with vs 2008 on win 7 and it's extremely frustrating. I have a simple console app project and no dependencies in terms of references except the default ones written in C#. Every now and then after debugging the exe will be locked. I find I have to wait 2 or 3 mins for it to be unlocked. It seems .net itself is locking it as I can close and reopen VS and it still be locked.
    Thursday, May 27, 2010 8:12 PM
  • I experienced this lovely issue as well. It appeared out of nowhere.

     

    VS2008 with SP1

    Windows Server 2008 R2

    No source code control

    VMWare

    The only possible lock was caused by devenv.exe itself, MSBUILD or as Andy stated the .NET framework itself.  I was using Process Monitor from sysinternals.com to aid me in an answer.

    The PreBuild suggestion worked the first time around and then the problem came back again.  Sadly, things turned for the worse when I was manually renaming the locked .DLL in question and deleting the obj\debug folder, in order to regain some dignity....too late.

    Thank you for posting this, BTW.

    Sunday, July 04, 2010 2:20 PM
  • I experience the same issue from time to time. In my case this is what I find to be helpful

    1) Make sure that the destination file in your \bin directory is not read-only.

    2) Delete your \obj directory

    3) ***This is often the magic step*** Check all of the other projects in your solution for the same issue. In my case, I was trying to build project B and B references project A and the error was in project A but since the error is reported back to you by VS with just relative path information you might not realize that the error is in a different (referenced) project than the project you are trying to build. Perform steps 1 and 2 in the referenced projects.

    Tuesday, July 20, 2010 2:05 PM
  • helpful one...

    thanks

    sam

    Thursday, July 22, 2010 9:09 AM

  • Peaches June's method solved my problem =)
    Thursday, August 12, 2010 6:03 AM
  • No solution yet. Nothing is working for me.
    Wednesday, August 18, 2010 8:33 PM
  • I've tried every workaround proposed online but none of them seem to be viable. 

    I am about to contact Microsoft Support; hopefully I will have a descent workaround.

     

    It is really frustrating to not be able to find a real workaround, especially when we know that VS developers have encountered this issue many times since VS2005 and hasn't been solved yet.

     

    Sincerely,

     

    • Proposed as answer by Mikepy Tuesday, August 31, 2010 11:45 AM
    Thursday, August 19, 2010 11:29 AM
  • I don't know if this will work for anyone else as it seems so simple!

    I tried most of the other suggestions but they didn't work so I just deleted the target blah.exe from the bin file !

     

    Has worked so far

     

    Mike

     

     


    Mike
    Tuesday, August 31, 2010 11:48 AM
  • I don't know what causes the issue, but here's what I did that seemed to work for me (other solutions above didn't) in VS2010:

    Modify C:\Windows\Microsoft.NET\Framework\v4.0.30319\Microsoft.Common.targets (back it up first).

    Was:

            <!-- Copy the build product (.dll or .exe). -->
            <Copy
                SourceFiles="@(IntermediateAssembly)"
                DestinationFolder="$(OutDir)"
                SkipUnchangedFiles="$(SkipCopyUnchangedFiles)"
                OverwriteReadOnlyFiles="$(OverwriteReadOnlyFiles)"
                Retries="$(CopyRetryCount)"
                RetryDelayMilliseconds="$(CopyRetryDelayMilliseconds)"
                UseHardlinksIfPossible="$(CreateHardLinksForCopyFilesToOutputDirectoryIfPossible)"
                Condition="'$(CopyBuildOutputToOutputDirectory)' == 'true' and '$(SkipCopyBuildProduct)' != 'true'"
                >

                <Output TaskParameter="DestinationFiles" ItemName="MainAssembly"/>
                <Output TaskParameter="DestinationFiles" ItemName="FileWrites"/>

            </Copy>

    Change to:

                Retries="60"
                RetryDelayMilliseconds="500"

    Not sure how to configure these normally but just change the file seemed to do the trick.

    (based on similar post here: http://codepolice.net/2010/02/22/problems-with-msbuild-tasks-after-playing-with-visual-studio-2010/)

    Jason

    Tuesday, October 19, 2010 8:12 AM
  • It very simple, just Exclude obj folder from the project solution window.

    As the error says "because it is being used by another process" , - Another process is none other then your own project.

     

    Thank You.

    With Regards

    Q.H. Ansari

    Owner/Proprietor:  http://www.asavebox.com

    Thursday, October 28, 2010 2:04 PM
  • Thanks, that took care of the problem
    Wednesday, February 09, 2011 5:18 PM
  • do we need to write Target or just copy paste this code

     

    Thursday, February 10, 2011 9:00 AM
  • > It very simple, just Exclude obj folder from the project solution window.

    How?


    TriSys Business Software
    Tuesday, February 15, 2011 10:02 AM
  • This is done by right clicking the obj folder in solution explorer, and choose "exclude from project".
    Monday, February 28, 2011 10:53 AM
  • Devenv.exe is blocking the file. I tried everything out here, but only one thing work - close visual studio and start it again. Then I can compile my project ONCE, second time it is in self blocking state again. Really annoying.

    • Proposed as answer by JapeD Friday, March 04, 2011 3:51 PM
    • Unproposed as answer by JapeD Friday, March 04, 2011 3:52 PM
    Thursday, March 03, 2011 3:56 AM
  • Devenv.exe is blocking the file. I tried everything out here, but only one thing work - close visual studio and start it again. Then I can compile my project ONCE, second time it is in self blocking state again. Really annoying.


    Same thing here ... I have VS 2010 an I tried everything out here too, only close visual studio and start it again helps :(
    • Proposed as answer by willyum2n Wednesday, March 09, 2011 8:25 PM
    • Unproposed as answer by willyum2n Wednesday, March 09, 2011 8:25 PM
    Friday, March 04, 2011 3:54 PM
  • First of all...thank you for all who have supplied your solutions.

    Second of all...none of the proposed solutions worked for me. However, I've worked out a solution that does work for me :)

    Thirdly...I'm going to get long winded for those of us who are new (This includes myself to a degree). Experts...bare with me.

     

    My Config:

     - OS = WinXP Pro SP3 32bit

     - IDE = VS2010 Pro

     - My Solution has 5 Projects in it. However, only 1 of the projects outputs an Executable (The other 4 are Class Libs [DLLs])

     

    ** NOTE ** To those of you who have not ventured beyond the standard, by default, project output goes into the folder for that particular project in the bin directory:

    - $(ProjectDir)Bin

    So if you have 5 Projects, you would have 5 different bin folders where files are being dumped to after compilation:

    Solution\Project#1\bin

     

    Solution\Project#2\bin

    Solution\Project#3\bin

    Solution\Project#4\bin

    Solution\Project#5\bin

     

    ** NOTE ** My Solution DOES NOT work the way the Note above describes

    I like having everything in one place, so I changed these defaults.

     - ALL of the output from ALL of my projects is being put into a single folder under the main Solution Directory. For each project of my projects I did the following:

    - [Project Properties] >> Build Tab >> Output Path = ..\Build\[Solution Config]

    - This means when in the:

    - Debug Config --> the output path = $(SolutionDir)Build\Debug

    - Release Config --> the output path = $(SolutionDir)Build\Release


     

    The directory manipulation I've done with my projects does nothing to help nor hinder the problems that we've all be facing with the IDE (VS2010 in my case) from erroring out with the [expletive here] "file in use" error. It just moves the problem to another folder.

     

    Ok...with all that said, here is what I've found in my case:

    At the Top of the Thread Mathew Wright stated [I'm going to paraphrase], move the lock file somewhere else. This got me on the right track. However, just moving the lock file wasn't enough for me. I also had to move the file it was locking against.

    The 2 Problem Files:

    I found that VS2010 was getting hung up on the Output from my EXE Project (Lets just call it "app"). In particular, it was:

    - App.exe

    - App.exe.locked

    VS2010 was actually generating a *.Locked file for each of my projects, but I found that it was the lock files for my EXE project that matttered. I was unable to Delete either of these file...period. Whether from the cmdline, or Explorer, or the Pre-Build(Just a commandline anyway...right?). However, I found that I COULD move the files (Thanks Matthew). What was interesting was, even though after I moved them, I still couldn't delete them. But that doesn't matter. The act of getting these 2 files out of my Build Directory fixes my issue.

    But this brings me to the next issue I had to overcome. Everybody have your MS-DOS hats on?!?! I've already stated that I can move the files, but I cannot delete them. Well, this means that they cannot be overwritten either. So putting a blanket statement of "Move app.exe to new folder" won't work. Even when you give the move command the /Y option. I get an "Access Denied" every time. But, I can rename the file during the move. So Here are the 3 command lines that I put in my Pre-Build to fix my problem:

     

    SET BaseName=%date:~10,4%%date:~4,2%%date:~7,2%_%time:~0,2%%time:~3,2%%time:~6,2%.%time:~9,2% 

    if exist "$(TargetPath).locked" move "$(TargetPath).locked" "$(SolutionDir)\build\trash\%BaseName%.locked" 

    if exist "$(TargetPath)" move /Y "$(TargetPath)" "$(SolutionDir)\build\trash\%BaseName%.exe"

    For those of you who do not remember (or know for that matter) you good ol' DOS commands, that first line is simply creating an Environment Variable that takes the current date and time and formats it into something that can be used in a file name. I believe you have to be careful in using the command above because it might change based on localization (??). To ensure that this isn't a problem, simple copy the line and paste it into your MS-DOS Command Prompt. After you have committed that line, type the following:

    echo %BaseName%

     You should end up with something like this "yyyyMMdd_HHmmss.ss". Then on the second command, it will use this string in the move command to get the EXE moved to a different directory (Trash), but it will change the filename from "app.exe.locked" to "yyyyMMdd_HHmmss.ss.locked". In this manner, there will never be a naming conflict! This follows for the 3rd line as well.

     

    Since I have done this, I've been able to compile to my hearts content (Barring any "real" problems). So, to re-cap, I followed these steps:

     - I centralized the output of all of my projects to a single folder (personal preference really)

     - In the Pre-Build I:

    - Create a string I can use for filenames based on the exact Date/Time in a format that can be used by the Filesystem

    - Move my app.exe.Locked file to a new directory using Unique Filename

    - Move my app.exe file to a new directory using Unique Filename.

     - Smile and shake my head knowing that this hack might not work after the next SP.

     

    Happy Coding and good luck to all of you. All the suggestions on this thread didn't fix me, but the definitely got me on my way. Thanks for all of the help!

    Will


     

     

     

    • Edited by willyum2n Wednesday, March 09, 2011 9:14 PM Added echo command
    Wednesday, March 09, 2011 9:10 PM
  • I am getting the same problem. My application was accessing some dlls from shared location. when i reconfigured my application after new windows installation, i started getting the same error. i just delete dlls from my project bin and then i build the application.

    My issue get resolved through this.

    Saturday, April 16, 2011 7:44 AM
  • willyum2n, that is a ridiculously clever solution! i was having the same problem and it fixed it right up, thank you for helping
    Saturday, May 28, 2011 10:21 PM
  • WillyUM2n,

     

    Thank you.  Awesome solution that has restored my sanity!  I am running Win 7 Pro x64 SP1 with VS2010 v10.0.30319.1.

     

    Regards,

    Larry

    Thursday, June 16, 2011 2:16 PM
  • Hi,

     

    Just to report there are two issues that cause this poblem. The first one is related with the auto increment version in assemblies (in assembly info, version = "1.0.*"). The solution proposed addresses that problem as reported in https://connect.microsoft.com/VisualStudio/feedback/details/571961/bug-on-build-solution-unable-to-copy-file-because-it-is-being-used-by-another-process.

    However, my problem is related to a class library which contains user controls, that are used in other projects in the same solution. This problem doesn't create any .locked files and using process explorer you can see that the file is locked by visual studio (devenv.exe). I think that the problem is related to the toolbox or the designer, as the toolbox will expose your user controls for drag and drop, and the designer will instantiate them and load the dll. At randon times (I think that if you open and close solutions a lot you will experience it more frequently) the visual studio ide, just don't release the dll and it get stuck in memory. Even I have found different versions of my dll in memory held by the ide. The only solution in this case is to close and reopen visual studio. None of the work arrounds proposed work. Closing and reopening the solution doesn't worked, closing any open designer windows doesn't worked, and resetting the toolbox doens't worked. I have been able to compile changing the platform or changing from debug to release, but it doesn't count as a workaround for me.

    In the bug report above you will see that many people are still experincing this problem without any solution. It is hard to reproduce, I haven't found a way, but it happens.

     

    Regards,

    MarianoC.

    Sunday, July 17, 2011 12:25 PM
  • I got this error and it was because I had some of my projects configured for Any CPU, my solution is for X86 and I have a X64 machine.  Once I had changed the configuration and set the paths correctly to X86 it was fine. (On Solution Right click-> Configuration Manager)
    Monday, July 25, 2011 12:40 PM
  • Hi,

    It's not my case. I have an X86 machine and all projects in my solution are configured to x86. Also it may seem to you that the problem was solved, because when you changed the platform, the directories changed and the locked files remain in the old directories for the other platform. Also if you change from debug to release you may think that you solved the problem. The problem is still there, and the files remain loaded in devenv.exe process and also, locked. I'm not the only one dealing with this issue, you can check the comments in the connect bug link I posted.

    Anyway thanks for your reply.

    Regards,

    MarianoC.

    Wednesday, July 27, 2011 2:29 PM
  • Thanks, you just saved me a restless night! +1
    "The improbable we do, the impossible just takes a little longer." (Steven Parker)
    Thursday, August 11, 2011 2:15 PM
  • I find setting Copy Local to false for the problem reference enables the application to compile.
    Dan Slaby
    Wednesday, August 24, 2011 1:55 AM
  • I came across a similar problem and it was due to my project references. For some reason my project had a reference to its own dll! I'm not sure how the reference got there but removing it fixed the locking issue for me.
    Wednesday, August 24, 2011 5:57 AM
  • As this hasn't been mentioned yet, my issue came from a new anti-malware I installed. The anti-malware disables specific application functionality to help protect the computer. However, some of these are required by visual studio to properly debug. So after allowing the visual studio process full access in my anti-malware, my problem was resolved.
    Thursday, August 25, 2011 3:27 PM
  • I was having the same issue.  I had recently installed Symantec 12 and that was the culprit. 
    Thursday, September 29, 2011 6:11 PM
  • My gawd. What a cluster!?

    I too am having the same problem, but there are no less than 10+ possible solutions above. Gah!
    • Edited by ITMn0403 Wednesday, November 02, 2011 5:24 PM
    Friday, September 30, 2011 7:02 PM
  • Hi, it looks like my problem, but I am not good in VS, could you describe how you changed paths? thx
    Thursday, October 20, 2011 12:49 PM
  • I have found something, I resolved it this way: I closed all opened designer files in VS, and restarted VS, then no problem
    • Proposed as answer by Ankouny Thursday, October 20, 2011 8:46 PM
    Thursday, October 20, 2011 1:32 PM
  • I had the same problem and I tried all of the stuff you guys mentioned but non of them worked, the only solution that worked for me is by going back to the root folder of my VS project and removed the READ ONLY Property from it.
    • Proposed as answer by Ankouny Thursday, October 20, 2011 8:46 PM
    Thursday, October 20, 2011 8:46 PM
  • I run into that all the time with nUnit.  I have to close it to release the files.  Be careful if you're using 3rd party hooks for debugging or testing.

    Friday, November 11, 2011 8:25 PM