Efcore: hostfxr.dll was found, but loading it from [hostfxr.dll path] failed

[daniel-li-djl87]

Trying to run the test cases in the source code (EFCore.Tests), but this error always occurs:

[7/8/2019 9:33:42 AM Error] Testhost process exited with error: Failed to load the dll from [C:\Users\Daniel Li\source\repos\EntityFrameworkCore.dotnethost\fxr\3.0.0-preview8-27905-07hostfxr.dll], HRESULT: 0x800700C1
The library hostfxr.dll was found, but loading it from C:\Users\Daniel Li\source\repos\EntityFrameworkCore.dotnethost\fxr\3.0.0-preview8-27905-07hostfxr.dll failed

• Installing .NET Core prerequisites might help resolve this problem.
  https://go.microsoft.com/fwlink/?linkid=798306

However, I think I have all the prerequisites installed:

Further technical details

OS Name: Microsoft Windows 10 Enterprise
IDE: Visual Studio Community 2019 Version 16.1.5
Microsoft .NET Framework Version 4.7.03056
.NET Core 3.0.100-preview6-012264 (in C:\Program Files\dotnet\sdk)

I can't seem to view the SDK version and runtime version with "dotnet --info", I get a similar output:

dotnet : Failed to load the dll from [C:\Users\Daniel Li\source\repos\EntityFrameworkCore.dotnethost\fxr\3.0.0-preview8-27905-07hostfxr.dll], HRESULT: 0x800700C1
At line:1 char:1

• dotnet --info
• ~~~~~
  
  
  
  • CategoryInfo : NotSpecified: (Failed to load ...ULT: 0x800700C1:String) [], RemoteException
  
  
  • FullyQualifiedErrorId : NativeCommandError
  
  

The library hostfxr.dll was found, but loading it from C:\Users\Daniel Li\source\repos\EntityFrameworkCore.dotnethost\fxr\3.0.0-preview8-27905-07hostfxr.dll failed

• Installing .NET Core prerequisites might help resolve this problem.
  https://go.microsoft.com/fwlink/?linkid=798306

[ajcvickers]

@daniel-li-djl87 Are you running build from the command line?

Note from triage: try on a clean machine.

[daniel-li-djl87]

Yes, I ran the build command and followed the instructions from: https://github.com/aspnet/EntityFrameworkCore/wiki/getting-and-building-the-code

[ajcvickers]

@daniel-li-djl87 I'll try it on a clean machine in the coming days and see if I can reproduce.

[ajcvickers]

@daniel-li-djl87 I tried on a clean machine and didn't run into any issues. I updated https://github.com/aspnet/EntityFrameworkCore/wiki/Getting-and-Building-the-Code to make a few things clearer. I tested with 16.1.5 Community Edition, with the "ASP.NET and web development" workload.

Some things to make sure of:

• build on the command line is working
• You are using startvs to open the Visual Studio solution

[daniel-li-djl87]

Thanks! I tried on a clean machine and I was able to get it to work.