NuGet Package restore failed: Microsoft.Bcl.Build.Tasks.dll used by another process

Question

NuGet Package restore failed for project MyProject.Application: The process cannot access the file 'C:\MySolution\packages\Microsoft.Bcl.Build.1.0.21\build/Microsoft.Bcl.Build.Tasks.dll' because it is being used by another process..

Any idea how to fix this issue? Thanks.

score 54 · Accepted Answer · answered Dec 08 '16 at 16:46

54

In Windows Explorer went to the folder where the NuGet packages are installed for my solution

<VS Solution>\packages\

and deleted all the Microsoft.Bcl.* folders. After that could rebuild the solution without problems.

answered Dec 08 '16 at 16:46

Ricardo stands with Ukraine

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Generally removing packages that appear in error helps. I had problem with Microsoft.Net.Compilers – cah1r Feb 05 '18 at 09:40
Killing msbuild.exe process is easy than deleting all NuGet packages in cases there are lots of packages needs to download. – Aamol May 29 '20 at 03:50

score 13 · Answer 2 · answered Oct 05 '17 at 21:05

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Find msbuild.exe in process explorer and kill it.

answered Oct 05 '17 at 21:05

Victorio Berra

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and kill devenv.exe – Scott Anderson Dec 05 '17 at 21:20

score 1 · Answer 3 · answered Sep 11 '18 at 17:24

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Try running this from an elevated command prompt:

taskkill /im devenv.exe

answered Sep 11 '18 at 17:24

StackThis

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score 0 · Answer 4 · answered Nov 24 '16 at 14:53

In my case this problem has occured after i installed an update for visual studio components.

As an option, you can try to uninstall Nuget plugin from Visual Studio, and install again (in Tools -> Extensions and Updates).

After that the problematic package successfully restored.

Symo · Answer 5 · 2018-05-04T10:46:13.897

Restarting Visual Studio seems to work - its seems to happen if you have multiple copies of VS open at some point - close all copies and it seems to fix it - for me its always Newtonsoft.json 11.0.2 that causes the issue for some reason. Also ending task on any MSBuild processes.

If you clear the NuGet cache (or delete the .nuget\packages folder the problem does not go away, which suggests the lock is happening during the restore process.

wbartussek · Answer 6 · 2018-08-07T18:40:42.173

Have a look at your .csproj file. If you find tags "PropertyGroup" and "ErrorText" with contents like:

"This project references NuGet package(s) that are missing on this computer. Use NuGet Package Restore to download them. For more information, see http://go.microsoft.com/fwlink/?LinkID=322105. The missing file is {0}."

you can safely delete these lines and store the altered .csproj file. Then you should be able to rebuild your project. This worked for me in several cases.

score 0 · Answer 7 · answered Apr 01 '19 at 21:33

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I was having lots of those while trying to restore nuget packages in the solution located on network drive. Just moving it to a local disk helped immediately

answered Apr 01 '19 at 21:33

Dmitry Duginov

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Saeid Babaei · Answer 8 · 2019-06-12T06:29:42.527

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Close Visual Studio and kill all msbuild.exe instances, Then delete Microsoft.Bcl* folders from packages folder.

edited Jun 12 '19 at 06:29

answered Jun 12 '19 at 06:21

Saeid Babaei

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NuGet Package restore failed: Microsoft.Bcl.Build.Tasks.dll used by another process

8 Answers8

"This project references NuGet package(s) that are missing on this computer. Use NuGet Package Restore to download them. For more information, see http://go.microsoft.com/fwlink/?LinkID=322105. The missing file is {0}."