@cpistiner Which MSBuild .csproj project type are you using? Are you using csproj Classic format or the Microsoft.Net.Sdk project format?

Also, what .NET Framework version or .NET Core Runtime are you running locally vs. on your server?

For .NET Core Runtime, not sure if you're aware, but it's easy to see which versions of .NET Core are installed on our machine.

In dotnet/standard#542 there are two suggestions:

• Check your Visual Studio version. Visual Studio 2017 15.4.4 contained a bug that was fixed in later versions - the code would work fine if you had the right MSBuild tool and SDK installed, but Visual Studio would fail
• Add the following in your csproj:

  <ItemGroup>
    <Reference Include="netstandard" />
  </ItemGroup>

Separately, as suggested:

• Report what csproj file format you are using
• Report what dotnet runtime you are building against
  • Is the runtime Core or Framework?
  • What version number for the given Core or Framework runtime?

MSBuild

Hi @jzabroski !

Thanks for your reply.

In localhost i have MSBuild 15.0 but the app is running in Windos Server 2012 and builds with MSBuil 14.0.

Also, what .NET Framework version or .NET Core Runtime are you running locally vs. on your server?

For .NET Core Runtime, not sure if you're aware, but it's easy to see which versions of .NET Core are installed on our machine.

4.6.1

This footnote / warning in the MS Docs might help you:

² The versions listed here represent the rules that NuGet uses to determine whether a given .NET Standard library is applicable. While NuGet considers .NET Framework 4.6.1 as supporting .NET Standard 1.5 through 2.0, there are several issues with consuming .NET Standard libraries that were built for those versions from .NET Framework 4.6.1 projects. For .NET Framework projects that need to use such libraries, we recommend that you upgrade the project to target .NET Framework 4.7.2 or higher.

Source: https://docs.microsoft.com/en-us/dotnet/standard/net-standard#net-implementation-support

In dotnet/standard#542 there are two suggestions:

• Check your Visual Studio version. Visual Studio 2017 15.4.4 contained a bug that was fixed in later versions - the code would work fine if you had the right MSBuild tool and SDK installed, but Visual Studio would fail
• Add the following in your csproj:

  <ItemGroup>
    <Reference Include="netstandard" />
  </ItemGroup>
  

Separately, as suggested:

• Report what csproj file format you are using

• Report what dotnet runtime you are building against

  • Is the runtime Core or Framework?
  • What version number for the given Core or Framework runtime?

At this moment i have Visual Stuidio Community 2019.

csproj file format? This?

The solution is running with NET Framework 4.6.1.

I already tried that but unfortunately it did not work

I thank you very much for the help, I hope that with this information we will find the solution.

Regards,
César

This footnote / warning in the MS Docs might help you:

2 The versions listed here represent the rules that NuGet uses to determine whether a given .NET Standard library is applicable. While NuGet considers .NET Framework 4.6.1 as supporting .NET Standard 1.5 through 2.0, there are several issues with consuming .NET Standard libraries that were built for those versions from .NET Framework 4.6.1 projects. For .NET Framework projects that need to use such libraries, we recommend that you upgrade the project to target .NET Framework 4.7.2 or higher.

Source: https://docs.microsoft.com/en-us/dotnet/standard/net-standard#net-implementation-support

Excelent this, I migrated to 4.7.2 and commented how it was!!

Thank you very much!

MSBuild

Hi @jzabroski !

Thanks for your reply.

In localhost i have MSBuild 15.0 but the app is running in Windos Server 2012 and builds with MSBuil 14.0.

MSBuild 14.0 likely does not support metapackages, or does not support metapackages at the same level as MSBuild 15.0 - I think you need to upgrade your build server, but first take a VM snapshot before following such destructive suggestions, so that if it fails, you can just rollback the snapshot.