Visual Studio build fails unable to copy exe-file from obj debug to bin debug

Question

Update  A sample project reproducing this bug can be found here at Microsoft Connect  I have also tested and verified that the solution given in the accepted answer below works on that sample project  If this solution doesn t work for you  you are probably having a different issue  which belongs in a separate question      This is a question asked before  both here on Stack Overflow and other places  but none of the suggestions I ve found this far has helped me  so I just have to try asking a new question   Scenario  I have a simple Windows Forms application  C    NET 4 0  Visual Studio 2010   It has a couple of base forms that most other forms inherit from  it uses Entity Framework  and POCO classes  for database access  Nothing fancy  no multi-threading or anything   Problem  All was fine for a while  Then  all out of the blue  Visual Studio failed to build when I was about to launch the application  I got the warning  Unable to delete file     bin Debug  ProjectName  exe   Access to the path     bin Debug  ProjectName  exe  is denied   and the error  Unable to copy file  obj x86 Debug  ProjectName  exe  to  bin Debug  ProjectName  exe   The process cannot access the file  bin Debug  ProjectName  exe  because it is being used by another process    I get both the warning and the error when running Rebuild  but only the error when running Build - don t think that is relevant    I understand perfectly fine what the warning and error message says  Visual Studio is obviously trying to overwrite the exe-file while it the same time has a lock on it for some reason  However  this doesn t help me find a solution to the problem    The only thing I ve found working is to shut down Visual Studio and start it again  Building and launching then works  untill I make a change in some of the forms  then I have the same problem again and have to restart    Quite frustrating   As I mentioned above  this seems to be a known problem  so there are lots of suggested solutions  I ll just list what I ve already tried here  so people know what to skip    Creating a new clean solution and just copy the files from the old solution  Adding the following to the following to the project s pre-build event   if exist    TargetPath  locked  del    TargetPath  locked     if not exist    TargetPath  locked  if exist    TargetPath   move    TargetPath      TargetPath  locked   Adding the following to the project properties   csproj file     lt GenerateResourceNeverLockTypeAssemblies gt true lt  GenerateResourceNeverLockTypeAssemblies gt     However  none of them worked for me  so you can probably see why I m starting to get a bit frustrated  I don t know where else to look  so I hope somebody has something to give me  Is this a bug in VS  and if so is there a patch  Or has I done something wrong  do I have a circular reference or similar  and if so how could I find out   Any suggestions are highly appreciated     Update  As mentioned in comment below  I ve also checked using Process Explorer that it actually is Visual Studio that is locking the file

User · Answer

When I have come across this problem it is to do with the Fact that the project I am trying to  build is set as the Startup project in the solution making the  exe in the obj folder locked   it also appears in your task manager   right click another project in your solution and choose set startup project  This will release the lock  remove it from task manager and should let you build

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Here s another possibility   After receiving this error in vs2012   win7  I went and tried to delete the file in the bin directory and explorer indicated that the file was in use by the XAML UI Designer   I closed all the tabs I had open in VS  closed VS  then made sure to kill all MSBuild processes in taskmanager  Finally  after restarting VS I was able to build the solution     and another possible cause   I have noticed another possible cause for this issue  After doing some code refactoring  moving projects in and out of a solution  my project references were no longer referencing the projects in the solution as expected   This mislead visual studio to think it could build some projects concurrently  thus creating the file locks   EDIT  I have had this happen on a few occasions even recently with VS2012 and it does fix it once I set the build order to the correct dependencies  kill any msbuild processes that VS left running  and then restart VS  I kill the msbuild processes just to be sure  but closing VS should kill them off too   What I usually do to cause this is refactor a project such that it relies on another project within the solution that it wasn t referencing on last build  This sometimes seem to confuse VS and it doesn t update the build order   To check build order  Right-click the Solution in the Solution Explorer and select  Project Build Order     and verify that dependencies are properly noted for each project

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I had same problem  It said could not copy from bin debug to obj       When i build web project i found my dll were all in bin folder and not in bin debug  During publish vs was looking for files in bin debug  So i opened web project file in editor and look for instances of bin debug and i found all the dll were mentioned as bin debug mylibrary dll  I removed all  debug from the path and published again  This time vs was able to find all the dll in bin folder and publish succeeded   I have no idea how this path got changed in web project file   I spent more than 5 hours debugging this and finally found solution on my own   This is the right answer

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Since I haven t gotten any more feedback on this issue  I thought I d just share what ended up being my solution   As suggested by Barry in a comment to the original post  manually renaming the     bin Debug ProjectName  exe  to something else  e g    ProjectName 1 exe   is one work-around  I m however not allowed to delete the file myself  and I must say I find that a bit weird as one would believe the same lock preventing deletion would also prevent renaming      It s not a good solution  but it s reasonable fast  at least after you ve done it a couple of times  it almost becomes a routine   and at least way faster than restarting Visual Studio which is what I did in the beginning   In case somebody wonders  I could also add that I only see this problem semi-randomly  It usually happens after I ve done some changes in the design mode of a form  but not always   It usually doesn t happen if I only change business-logic code or non-visual related code  but sometimes it does      Frustrating indeed  but at least I have a hack that works for me - let s just hope that my next project doesn t face this problem as well      Barry  if you would like to get credit for your comment  please feel free to post it as an answer and I ll make sure to accept it

User · Answer

When I faced a similar issue  the only thing that seemed to work was    Right click the project  going to Settings  and making sure that both Debug and Release builds target the same settings  or have the settings in there that the application tries to load or save  Deleting the C  Users YourUserAccount  AppData Local YourAppName  folder  Making sure that no files that I had in there were considered  Blocked   Right-clicking my project s included files  I realized that one icon was actually blocked and considered bad because it was downloaded from the internet  I had to click the Unblock button  in example  check this out  http   devierkoeden com Images Articles Dynamicweb CustomModules Part1 BlockedFiles png -  This file came from another computer and might be blocked to help protect this computer

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Do the simple things first   Check that part of your solution is not locked by a running process   For instance  I ran  InstallUtil   on my windows service which I normally unit test from a console    This locked some of my dlls in the bin folder of the windows service project  When I did a rebuild I got the exception in this issue   I stopped the windows service  rebuilt and it succeeded   Check Windows Task Manager for your Application  before doing any of the advance steps in this issue   So when you hear footsteps  think horses not zebras   from medical student friend

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This is rather commonly caused by Avast     I can usually run my projects in Release regardless  but when running in debug it would pretty regularly fail     I just add an exclusion for my projects folder and the problem seems to go away   I assume this might also be cause by other antivirus software

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I faced the same error   I solved the problem by deleting all the contents of bin folders of all the dependent projects libraries   This error mainly happens due to version changes

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If none of the above works  and you are developing a console application   Try typing any character into Program cs  then delete it  I have no idea why this works  but it seems to resolve  Unable to copy  problem every time

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I know this is a very old question  but I recently experienced the  cannot copy from obj to bin  error in VS 2012  Every single time I tried to rebuild a certain project  I got the message  The only solution was to do a clean before every rebuild    After much investigating  it turns out I had an incomplete pragma warning statement in one of my files that did not prevent the compilation from succeeding  but was somehow confusing VS into keeping the file s  locked   In my case  I had the following at the top of the file    pragma warning    That s it  I guess I was attempting to do something a while back and got distracted and never finished the process  but the VS warnings about that particular line were lost in the shuffle  Eventually I noticed the warning  removed the line  and rebuild works every time since then

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I tried several solutions that you provided  but occasionally I still receive this error  I am positive that my process is not running  and when i try to delete the executable file with internet explorer it is removed from the file list  but then I press F5 and voila  the file is back  It has not been deleted at all    But if i delete the file through the TotalCommander  the exe file is actually deleted and I can successfully build the project   I am using windows 7 x64 and total commander 7 56a 32 bit

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Re-enabling the Application Experience service of Windows has fixed that kind of problems for me   See the following links    Visual Studio output file permissions  Under which circumstances does the System process  PID 4  retain an open file handle    I had the problem using Visual Studio 2008  2010 and 2013 with Windows 7 64-bit

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This helps for me after i remove read only flag from bin directory  http   www thewindowsclub com error-0x80080015-windows-defender-activation-requires-display-name

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Restart IIS- could be a process attached to the debugger

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I also had a problem very similar to this and found the reason in my case was that I had made the bin debug folder available as a shared folder under VMware and either VMware  Explorer under the VM guest  or maybe even an anti-virus program under the guest  though I don t think I had one installed  was holding a handle to the file s

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I have the same problem  MSB3021  with WPF project in VS2008  on Windows 7 x32   The problem appearing if i try to re-run application too quick after previous run  After a few minutes exe-file unlocked by itself and i can re-run application again  But such a long pause angers me  The only thing that really helped me was running VS as Administrator

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My solution has nothing to do with versions  processes being locked  restarting  or deleting files   The problem was actually due to the build failing  and not giving the correct error  The actual problem was a design flaw      Either this should be declared outside the function  or   SomeObject a   new SomeObject      Task Factory StartNew      gt       while  true             a waitForSomething                    this should not be called a doSomething       After changing the scope of  a  to outside the function  or not using  a  after Task Factory StartNew     I was able to build again   This happened when using VS2012 Update 4 on Windows7x64 sp1   Error message       C  Windows Microsoft NET Framework v4 0 30319 Microsoft Common targets 3390 5     error MSB3030  Could not copy the file  obj x86 Debug xxx exe  because   it was not found

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Renaming the  exe and  pub file worked for me  but really tedious  I also face the problem that I could not do editing during a debug session  Finally I went to the Advanced Security Setting Page  as per   https   msdn microsoft com query dev10 query appId Dev10IDEF1 amp l EN-US amp k k 28 22VS ERR DEBUG IN ZONE NO HOSTPROC 3a11310 22 29 k 28TargetFrameworkMoniker- 22 NETFRAMEWORK 2cVERSION 3dV4 0 22 29 amp rd true  I  un-select then re-select the  Enable ClickOnce security settings  checkbox  It s been problem free for some days now

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Solved  Unable to copy exe-file from obj debug to bin debug   I am approaching that you get this error while you was trying to run two windows form one after another such as first loading a form then after sometimes it will automatically disappear and the second form loaded onto the screen   Basically  you need to close your first form which is running in the background and the main reason behind this error   To close the first form you have to add these two lines of code in the second form load event handler           Form1 form   new Form1            form Close      This will solve the error perfectly

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I tried all the other suggestions in the answers here  none of which worked  Eventually I used Process Monitor to discover that my  exe that VS2010 was failing to build was locked by the System process  PID 4   Searching SO for situations involving this yielded this answer   Summarised  if you have the Application Experience service disabled  as I did  then re-enable and start it  Two years of aggravation ended

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This has been filed multiple times on Connect  Microsoft s community bug reporting site   FYI  I believe this bug has afflicted Visual Studio since 2003 and has been fixed after RTM each time      One of the references is as follows   https   connect microsoft com VisualStudio feedback details 568672 handles-to-project-dlls-are-not-released-when-compiling wa wsignin1 0

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Disable antivirus and try  I was also facing that problem    but in my case antivirus was blocking my application when I disabled antivirus it resolved

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Using Visual Studio I could never come up with a simple project to reproduce the error   My solution was to disable the Visual Studio Hosting process   For those interested I have attached a handle trace for the offending handle   0 044 gt   htrace 242C -------------------------------------- Handle   0x000000000000242c - OPEN Thread ID   0x0000000000001cd0  Process ID   0x0000000000001a5c  0x000000007722040a  ntdll ZwCreateFile 0x000000000000000a 0x0000000074b4bfe3  wow64 whNtCreateFile 0x000000000000010f 0x0000000074b3cf87  wow64 Wow64SystemServiceEx 0x00000000000000d7 0x0000000074ac276d  wow64cpu TurboDispatchJumpAddressEnd 0x0000000000000024 0x0000000074b3d07e  wow64 RunCpuSimulation 0x000000000000000a 0x0000000074b3c549  wow64 Wow64LdrpInitialize 0x0000000000000429 0x00000000772184c8  ntdll LdrpInitializeProcess 0x00000000000017e2 0x0000000077217623  ntdll       FNODOBFM   string  0x000000000002bea0 0x000000007720308e  ntdll LdrInitializeThunk 0x000000000000000e 0x00000000773d0066  ntdll 773b0000 NtCreateFile 0x0000000000000012 0x000000007541b616  KERNELBASE CreateFileW 0x000000000000035e 0x0000000075b42345  KERNEL32 CreateFileWImplementation 0x0000000000000069 0x000000006a071b47  mscorwks ntdef StgIO  Open 0x000000000000028c -------------------------------------- Handle   0x000000000000242c - CLOSE Thread ID   0x0000000000000cd4  Process ID   0x0000000000001a5c  0x000000007721ffaa  ntdll ZwClose 0x000000000000000a 0x0000000074b3f2cd  wow64 whNtClose 0x0000000000000011 0x0000000074b3cf87  wow64 Wow64SystemServiceEx 0x00000000000000d7 0x0000000074ac276d  wow64cpu TurboDispatchJumpAddressEnd 0x0000000000000024 0x0000000074b3d07e  wow64 RunCpuSimulation 0x000000000000000a 0x0000000074b3c549  wow64 Wow64LdrpInitialize 0x0000000000000429 0x000000007724d177  ntdll       FNODOBFM   string  0x000000000002bfe4 0x000000007720308e  ntdll LdrInitializeThunk 0x000000000000000e 0x00000000773cf992  ntdll 773b0000 ZwClose 0x0000000000000012 0x0000000075b42642  KERNEL32 BaseRegCloseKeyInternal 0x0000000000000041 0x0000000075b425bc  KERNEL32 RegCloseKey 0x000000000000007d     WARNING  Unable to verify checksum for mscorlib ni dll 0x0000000068f13ca3  mscorlib ni 0x0000000000233ca3 0x0000000069bc21db  mscorwks ntdef CallDescrWorker 0x0000000000000033 0x0000000069be4a2a  mscorwks ntdef CallDescrWorkerWithHandler 0x000000000000008e -------------------------------------- Handle   0x000000000000242c - OPEN Thread ID   0x00000000000006cc  Process ID   0x0000000000001a5c  0x0000000077220e0a  ntdll NtOpenKeyEx 0x000000000000000a 0x0000000074b5d1c9  wow64 Wow64NtOpenKey 0x0000000000000091 0x0000000074b5313b  wow64 whNtOpenKeyEx 0x0000000000000073 0x0000000074b3cf87  wow64 Wow64SystemServiceEx 0x00000000000000d7 0x0000000074ac276d  wow64cpu TurboDispatchJumpAddressEnd 0x0000000000000024 0x0000000074b3d07e  wow64 RunCpuSimulation 0x000000000000000a 0x0000000074b3c549  wow64 Wow64LdrpInitialize 0x0000000000000429 0x000000007724d177  ntdll       FNODOBFM   string  0x000000000002bfe4 0x000000007720308e  ntdll LdrInitializeThunk 0x000000000000000e 0x00000000773d0fca  ntdll 773b0000 NtOpenKeyEx 0x0000000000000012 0x0000000075b42721  KERNEL32 LocalBaseRegOpenKey 0x000000000000010c 0x0000000075b428c9  KERNEL32 RegOpenKeyExInternalW 0x0000000000000130 0x0000000075b427b5  KERNEL32 RegOpenKeyExW 0x0000000000000021 -------------------------------------- Handle   0x000000000000242c - CLOSE Thread ID   0x0000000000000cd4  Process ID   0x0000000000001a5c  0x000000007721ffaa  ntdll ZwClose 0x000000000000000a 0x0000000074b3f2cd  wow64 whNtClose 0x0000000000000011 0x0000000074b3cf87  wow64 Wow64SystemServiceEx 0x00000000000000d7 0x0000000074ac276d  wow64cpu TurboDispatchJumpAddressEnd 0x0000000000000024 0x0000000074b3d07e  wow64 RunCpuSimulation 0x000000000000000a 0x0000000074b3c549  wow64 Wow64LdrpInitialize 0x0000000000000429 0x000000007724d177  ntdll       FNODOBFM   string  0x000000000002bfe4 0x000000007720308e  ntdll LdrInitializeThunk 0x000000000000000e 0x00000000773cf992  ntdll 773b0000 ZwClose 0x0000000000000012 0x0000000075b42642  KERNEL32 BaseRegCloseKeyInternal 0x0000000000000041 0x0000000075b425bc  KERNEL32 RegCloseKey 0x000000000000007d 0x0000000068f13ca3  mscorlib ni 0x0000000000233ca3 0x0000000069bc21db  mscorwks ntdef CallDescrWorker 0x0000000000000033 0x0000000069be4a2a  mscorwks ntdef CallDescrWorkerWithHandler 0x000000000000008e -------------------------------------- Handle   0x000000000000242c - OPEN Thread ID   0x0000000000001cd0  Process ID   0x0000000000001a5c  0x0000000077220e0a  ntdll NtOpenKeyEx 0x000000000000000a 0x0000000074b5d1c9  wow64 Wow64NtOpenKey 0x0000000000000091 0x0000000074b5313b  wow64 whNtOpenKeyEx 0x0000000000000073 0x0000000074b3cf87  wow64 Wow64SystemServiceEx 0x00000000000000d7 0x0000000074ac276d  wow64cpu TurboDispatchJumpAddressEnd 0x0000000000000024 0x0000000074b3d07e  wow64 RunCpuSimulation 0x000000000000000a 0x0000000074b3c549  wow64 Wow64LdrpInitialize 0x0000000000000429 0x00000000772184c8  ntdll LdrpInitializeProcess 0x00000000000017e2 0x0000000077217623  ntdll       FNODOBFM   string  0x000000000002bea0 0x000000007720308e  ntdll LdrInitializeThunk 0x000000000000000e 0x00000000773d0fca  ntdll 773b0000 NtOpenKeyEx 0x0000000000000012 0x0000000075b42721  KERNEL32 LocalBaseRegOpenKey 0x000000000000010c 0x0000000075b428c9  KERNEL32 RegOpenKeyExInternalW 0x0000000000000130 -------------------------------------- Handle   0x000000000000242c - CLOSE Thread ID   0x0000000000000cd4  Process ID   0x0000000000001a5c  0x000000007721ffaa  ntdll ZwClose 0x000000000000000a 0x0000000074b3f2cd  wow64 whNtClose 0x0000000000000011 0x0000000074b3cf87  wow64 Wow64SystemServiceEx 0x00000000000000d7 0x0000000074ac276d  wow64cpu TurboDispatchJumpAddressEnd 0x0000000000000024 0x0000000074b3d07e  wow64 RunCpuSimulation 0x000000000000000a 0x0000000074b3c549  wow64 Wow64LdrpInitialize 0x0000000000000429 0x000000007724d177  ntdll       FNODOBFM   string  0x000000000002bfe4 0x000000007720308e  ntdll LdrInitializeThunk 0x000000000000000e 0x00000000773cf992  ntdll 773b0000 ZwClose 0x0000000000000012 0x0000000075b42642  KERNEL32 BaseRegCloseKeyInternal 0x0000000000000041 0x0000000075b425bc  KERNEL32 RegCloseKey 0x000000000000007d 0x0000000068f13ca3  mscorlib ni 0x0000000000233ca3 0x0000000069bc21db  mscorwks ntdef CallDescrWorker 0x0000000000000033 0x0000000069be4a2a  mscorwks ntdef CallDescrWorkerWithHandler 0x000000000000008e -------------------------------------- Handle   0x000000000000242c - OPEN Thread ID   0x0000000000001cd0  Process ID   0x0000000000001a5c  0x0000000077220e0a  ntdll NtOpenKeyEx 0x000000000000000a 0x0000000074b5d1c9  wow64 Wow64NtOpenKey 0x0000000000000091 0x0000000074b5313b  wow64 whNtOpenKeyEx 0x0000000000000073 0x0000000074b3cf87  wow64 Wow64SystemServiceEx 0x00000000000000d7 0x0000000074ac276d  wow64cpu TurboDispatchJumpAddressEnd 0x0000000000000024 0x0000000074b3d07e  wow64 RunCpuSimulation 0x000000000000000a 0x0000000074b3c549  wow64 Wow64LdrpInitialize 0x0000000000000429 0x00000000772184c8  ntdll LdrpInitializeProcess 0x00000000000017e2 0x0000000077217623  ntdll       FNODOBFM   string  0x000000000002bea0 0x000000007720308e  ntdll LdrInitializeThunk 0x000000000000000e 0x00000000773d0fca  ntdll 773b0000 NtOpenKeyEx 0x0000000000000012 0x0000000075b42721  KERNEL32 LocalBaseRegOpenKey 0x000000000000010c 0x0000000075b428c9  KERNEL32 RegOpenKeyExInternalW 0x0000000000000130  -------------------------------------- Parsed 0x358E stack traces  Dumped 0x7 stack traces  0 044 gt   handle 242c ff Handle 242c   Type          File   Attributes    0   GrantedAccess 0x120089           ReadControl Synch          Read List ReadEA ReadAttr   HandleCount   2   PointerCount  3   No Object Specific Information available

User · Answer

For Windows Services using WCF  I ended the WFC host process and it worked  I hate it when this happens  and it happens randomly at times

User · Answer

For me this was being caused by having a command prompt open in the targeted folder  C  users username source repos project project bin debug app publish    Not sure why DEBUGGING requires access to the publish folder  but closing the command window solved the issue for me

User · Answer

IF YOUR PROBLEM IS NOT SOLVED YET   Visual studio s error is     The process cannot access the file  bin Debug  app exe    because it is being used by another process    So  go to task manager of windows Ctrl Shift Esc  find your application name  and force it to close by Endprocces

User · Answer

This is going to sound stupid  but I tried all these solutions  running VS2010 on Windows 7  None of them worked except the renaming and building  which was VERY tedious to say the least  Eventually  I tracked down the culprit  and I find it hard to believe  But I was using the following code in AssemblyInfo cs      assembly  AssemblyVersion  2 0        This is pretty common  but for some reason  changing the version to 2 0 0 0 made things work again  I don t know if it s a Windows 7 specific thing  I ve only been using it for 3-4 weeks   or if it s random  or what  but it fixed it for me  I m guessing that VS was keeping a handle on each file it generated  so it would know how to increment things  I m really not sure and have never seen this happen before  But if someone else out there is also pulling their hair out  give it a try

User · Answer

I d suggest download Process Explorer to find out exactly what process is locking the file  It can be found at   http   technet microsoft com en-us sysinternals bb896653 aspx

User · Answer

None of the other answers worked for me but closing all open tabs in Visual Studio appears to have solved the problem

User · Answer

I have found with VS2013 I get this error regularly   Something that seems to work reasonably well is to  perform a Rebuild Solution prior trying to run the application   I found that performing a CLEAN sometimes works  but the Rebuild Solution seems to work more consistently

User · Answer

One thing that really helped me was adding the   exe  on the Debug folder to the Exclusions on my Anti-Virus

User · Answer

I found one simple solution  just disable the Windows Indexing Services for the project folder and subfolders

User · Answer

Set another project as startup Build the project  the non problematic project will display  Go to the problematic bin debug folder Rename myservice vshost exe to myservice exe

User · Answer

In case somebody is running into this while trying to debug a Unit Test or Run a unit test I had to kill the following two processes in order for it to release the file

User · Answer

Disable  Enable the Visual Studio hosting process

[c#] Visual Studio build fails: unable to copy exe-file from obj\debug to bin\debug

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