The "CheckFileSystemCaseSensitive" task failed unexpectedly, Could not load file or assembly 'System.IO.FileSystem

Question

To my Visual Studio 2017, ASP.NET Core, MVC web project I just added the Microsoft.TypeScript.MSBuild NuGet package v2.3.1, and simultaneously updated my ASP.NET Core assemblies from 1.0.* to 1.1.1. Now suddenly when I build my project I get the following exception:

Severity    Code    Description Project File    Line    Suppression State
Error   MSB4018 The "CheckFileSystemCaseSensitive" task failed unexpectedly.
System.IO.FileNotFoundException: Could not load file or assembly 'System.IO.FileSystem, Version=4.0.1.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a' or one of its dependencies. The system cannot find the file specified.
File name: 'System.IO.FileSystem, Version=4.0.1.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a'
   at TypeScript.Tasks.CheckFileSystemCaseSensitive.Execute()
   at Microsoft.Build.BackEnd.TaskExecutionHost.Microsoft.Build.BackEnd.ITaskExecutionHost.Execute()
   at Microsoft.Build.BackEnd.TaskBuilder.<ExecuteInstantiatedTask>d__26.MoveNext()

Double-clicking on the exception message takes one to these lines in the file Microsoft.TypeScript.targets:

<Target Name="CheckFileSystemCaseSensitive">
    <CheckFileSystemCaseSensitive
       MSBuildThisFileFullPath="$(MSBuildThisFileFullPath)" >
      <Output TaskParameter="IsFileSystemCaseSensitive"  PropertyName="IsFileSystemCaseSensitive" />
    </CheckFileSystemCaseSensitive>
</Target>

where it says that "MSBuildThisFileFullPath is not defined".

I've tried adding references to NETStandard.Library, as suggested here: https://github.com/dotnet/corefx/issues/16206, but that doesn't make any difference.

The diagnostic MSBuild output looks like this:

1>Target "CheckFileSystemCaseSensitive" in file "C:\Users\dkent\.nuget\packages\microsoft.typescript.msbuild\2.3.1\tools\netstandard1.3\Microsoft.TypeScript.targets":
1>  Using "CheckFileSystemCaseSensitive" task from assembly "C:\Users\dkent\.nuget\packages\microsoft.typescript.msbuild\2.3.1\tools\netstandard1.3\TypeScript.Tasks.dll".
1>  Task "CheckFileSystemCaseSensitive"
1>    Task Parameter:MSBuildThisFileFullPath=C:\Users\dkent\.nuget\packages\microsoft.typescript.msbuild\2.3.1\tools\netstandard1.3\Microsoft.TypeScript.targets
1>    [...]\.nuget\packages\microsoft.typescript.msbuild\2.3.1\tools\netstandard1.3\Microsoft.TypeScript.targets(172,5): error MSB4018: The "CheckFileSystemCaseSensitive" task failed unexpectedly.
1>    [...]\.nuget\packages\microsoft.typescript.msbuild\2.3.1\tools\netstandard1.3\Microsoft.TypeScript.targets(172,5): error MSB4018: System.IO.FileNotFoundException: Could not load file or assembly 'System.IO.FileSystem, Version=4.0.1.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a' or one of its dependencies. The system cannot find the file specified.
1>    [...]\.nuget\packages\microsoft.typescript.msbuild\2.3.1\tools\netstandard1.3\Microsoft.TypeScript.targets(172,5): error MSB4018: File name: 'System.IO.FileSystem, Version=4.0.1.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a'
1>    [...]\.nuget\packages\microsoft.typescript.msbuild\2.3.1\tools\netstandard1.3\Microsoft.TypeScript.targets(172,5): error MSB4018:    at TypeScript.Tasks.CheckFileSystemCaseSensitive.Execute()
1>    [...]\.nuget\packages\microsoft.typescript.msbuild\2.3.1\tools\netstandard1.3\Microsoft.TypeScript.targets(172,5): error MSB4018:    at Microsoft.Build.BackEnd.TaskExecutionHost.Microsoft.Build.BackEnd.ITaskExecutionHost.Execute()
1>    [...]\.nuget\packages\microsoft.typescript.msbuild\2.3.1\tools\netstandard1.3\Microsoft.TypeScript.targets(172,5): error MSB4018:    at Microsoft.Build.BackEnd.TaskBuilder.<ExecuteInstantiatedTask>d__26.MoveNext()
1>  Done executing task "CheckFileSystemCaseSensitive" -- FAILED.

Thanks for any suggestions.

Answer 1

I had the same error in Vs2015, i installed type script from https://www.microsoft.com/en-us/download/confirmation.aspx?id=48593 , and the error disappeared, you could give a try

Answer 2

(old question, but this may help anyone else looking for a solution to this issue):

As an alternative way of configuring TypeScript for your VS project, you can try adding the Microsoft TypeScript Compiler nuget package to the solution instead of the Microsoft.TypeScript.MSBuild package. You may need to configure the <TypeScriptToolsVersion> in the .csproj file (you only need the minor and major version e.g.):

<TypeScriptToolsVersion>2.3</TypeScriptToolsVersion>