Nuget package installation issue in VS2019 + Dotnet Framework 4.7.2

Question

I am getting an error when trying to install nuget package in .net framework 4.7.2 application:

System.IO.IOException: The process cannot access the file 'D:\PP\packages\Newtonsoft.Json.12.0.2\lib\netstandard1.3\Newtonsoft.Json.dll' because it is being used by another process.
   at System.IO.__Error.WinIOError(Int32 errorCode, String maybeFullPath)
   at System.IO.FileStream.Init(String path, FileMode mode, FileAccess access, Int32 rights, Boolean useRights, FileShare share, Int32 bufferSize, FileOptions options, SECURITY_ATTRIBUTES secAttrs, String msgPath, Boolean bFromProxy, Boolean useLongPath, Boolean checkHost)
   at System.IO.FileStream..ctor(String path, FileMode mode, FileAccess access, FileShare share, Int32 bufferSize)
   at System.IO.File.OpenFile(String path, FileAccess access, SafeFileHandle& handle)
   at System.IO.File.SetLastWriteTimeUtc(String path, DateTime lastWriteTimeUtc)
   at NuGet.Packaging.PackageFolderReader.CopyFiles(String destination, IEnumerable`1 packageFiles, ExtractPackageFileDelegate extractFile, ILogger logger, CancellationToken token)
   at NuGet.Packaging.PackageReaderBase.CopyFilesAsync(String destination, IEnumerable`1 packageFiles, ExtractPackageFileDelegate extractFile, ILogger logger, CancellationToken cancellationToken)
   at NuGet.Packaging.PackageExtractor.<ExtractPackageAsync>d__1.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.ValidateEnd(Task task)
   at NuGet.ProjectManagement.FolderNuGetProject.<>c__DisplayClass13_0.<<InstallPackageAsync>b__0>d.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at NuGet.Common.ConcurrencyUtilities.<ExecuteWithFileLockedAsync>d__2`1.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.ValidateEnd(Task task)
   at NuGet.ProjectManagement.MSBuildNuGetProject.<InstallPackageAsync>d__36.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at NuGet.PackageManagement.NuGetPackageManager.<ExecuteInstallAsync>d__85.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.ValidateEnd(Task task)
   at NuGet.PackageManagement.NuGetPackageManager.<ExecuteNuGetProjectActionsAsync>d__76.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at NuGet.PackageManagement.NuGetPackageManager.<ExecuteNuGetProjectActionsAsync>d__76.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at NuGet.PackageManagement.NuGetPackageManager.<ExecuteNuGetProjectActionsAsync>d__76.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at NuGet.PackageManagement.NuGetPackageManager.<ExecuteNuGetProjectActionsAsync>d__75.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.ValidateEnd(Task task)
   at NuGet.PackageManagement.NuGetPackageManager.<ExecuteNuGetProjectActionsAsync>d__74.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at NuGet.PackageManagement.UI.UIActionEngine.<ExecuteActionsAsync>d__17.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.ValidateEnd(Task task)
   at NuGet.PackageManagement.UI.UIActionEngine.<>c__DisplayClass12_0.<<PerformActionImplAsync>b__0>d.MoveNext()
Time Elapsed: 00:00:00.9362158
========== Finished ==========

Env. Details:

Name : Package Manager Host
Version : 5.4.0.6292
Visual Studio 2019 version: 16.4.5
Application version: .Net Framework version 4.7.2

Steps tried so far:

1. I have restarted my machine and tried again but still the same issue.
2. Able to install the nuget package successfully in blank dotnet framework project.

Answer 1

The process cannot access the file 'xxxxxxxNewtonsoft.Json.dll' because it is being used by another process.

As the error said, the nuget package is controled by another process. You can try these steps:

1) first delete the all nuget packages in the global nuget cache under C:\Users\xxx\.nuget\packages or use clean nuget caches.

Also, delete the packages folder under your solution path(like D:\PP\).

2) close VS Instance, delete .vs hidden folder, bin, obj folder.

3) If you find msbuild.exe and devenv.exe in process explorer, please kill them.

4) disable antivirus for the moment

5) restart your project in VS, and try step 3 and then run restore(Right-click on the solution-->Restore Nuget Packages) to restore the installed packages and then try to install Newtonsoft.Json nuget package again.