Unable to build with visual studio, dotnet build works.

[YashC]

Building with 'dotnet build' using quick start instructions works fine but running build or testing in Visual Studio fails with following error. I'm currently using release/6.0 branch for testing.

Error MSB4018 The "ChooseBestP2PTargetFrameworkTask" task failed unexpectedly.
System.IO.FileNotFoundException: Could not load file or assembly 'Newtonsoft.Json, Version=9.0.0.0, Culture=neutral, PublicKeyToken=30ad4fe6b2a6aeed' or one of its dependencies. The system cannot find the file specified.
File name: 'Newtonsoft.Json, Version=9.0.0.0, Culture=neutral, PublicKeyToken=30ad4fe6b2a6aeed'
at NuGet.RuntimeModel.JsonRuntimeFormat.ReadRuntimeGraph(TextReader textReader)
at NuGet.RuntimeModel.JsonRuntimeFormat.ReadRuntimeGraph(Stream stream)
at NuGet.RuntimeModel.JsonRuntimeFormat.ReadRuntimeGraph(String filePath)
at Microsoft.DotNet.Build.Tasks.TargetFramework.Sdk.TargetFrameworkResolver..ctor(String runtimeGraph) in //src/Microsoft.DotNet.Build.Tasks.TargetFramework.Sdk/src/TargetFrameworkResolver.cs:line 24
at Microsoft.DotNet.Build.Tasks.TargetFramework.Sdk.ChooseBestP2PTargetFrameworkTask.Execute() in //src/Microsoft.DotNet.Build.Tasks.TargetFramework.Sdk/src/ChooseBestP2PTargetFrameworkTask.cs:line 27
at Microsoft.Build.BackEnd.TaskExecutionHost.Microsoft.Build.BackEnd.ITaskExecutionHost.Execute()
at Microsoft.Build.BackEnd.TaskBuilder.d__26.MoveNext()

WRN: Assembly binding logging is turned OFF.
To enable assembly bind failure logging, set the registry value [HKLM\Software\Microsoft\Fusion!EnableLog] (DWORD) to 1.
Note: There is some performance penalty associated with assembly bind failure logging.
To turn this feature off, remove the registry value [HKLM\Software\Microsoft\Fusion!EnableLog].
System.Net.Security.Unit.Tests C:\Users***.nuget\packages\microsoft.dotnet.build.tasks.targetframework.sdk\6.0.0-beta.22457.3\build\Microsoft.DotNet.Build.Tasks.TargetFramework.Sdk.targets 84

Any suggestions or tips would be helpful to resolve this issue?

[Connor14]

@YashC I have also run into this exact same issue. Did you happen to figure out how to fix it?

[Connor14]

In my case I was building from the v6.0.10 tag.

I managed to work around this issue by manually copying the Newtonsoft.Json.dll from Newtonsoft.Json v9.0.1 (downloaded via NuGet) into ~\.nuget\packages\microsoft.dotnet.build.tasks.targetframework.sdk\6.0.0-beta.22463.7\tools\net472 and ~\.nuget\packages\microsoft.dotnet.build.tasks.targetframework.sdk\6.0.0-beta.22463.7\tools\netcoreapp3.1 directories. I renamed the original Newtonsoft.Json.dll files to Newtonsoft.Json.dll.old just for the sake of keeping them around.

Once I closed and reopened Visual Studio I was able to build the Microsoft.Extensions.Http library successfully.

[Connor14]

This certainly isn't the right way to resolve this issue, but it got me moving again!