T4 cannot find netstandard 2.1

[Emdot]

When a T4 compile-time template references a netstandard 2.1 assembly, if the template's code tries to instantiate a class from that assembly it generates an error:

Running transformation: System.IO.FileNotFoundException: Could not load file or assembly 'netstandard, Version=2.1.0.0, Culture=neutral, PublicKeyToken=cc7b13ffcd2ddd51' or one of its dependencies. The system cannot find the file specified.
File name: 'netstandard, Version=2.1.0.0, Culture=neutral, PublicKeyToken=cc7b13ffcd2ddd51'
   at Microsoft.VisualStudio.TextTemplatingDF0B46F7DFCCCF2CAD1FBB2E3A8D5FC6225E74132FDDBD12D44030F822D8B29A6DFFE0B2FED81F4BED62AEA63823EBB5C1182E33103987C1DA7368F9D1022F09.GeneratedTextTransformation.TransformText()
   at System.Dynamic.UpdateDelegates.UpdateAndExecute1[T0,TRet](CallSite site, T0 arg0)
   at Microsoft.VisualStudio.TextTemplating.TransformationRunner.PerformTransformation()

This occurs even if the project containing the T4 template targets netstandard 2.1.

Test case attached: just right-click TT.tt and select Run Custom Tool. The error message appears.

NetStandardT4.zip

Microsoft Visual Studio Community 2019, v 16.4.0; 64-bit PC; 64-bit Windows 10. I'm using the Devart Template Editor extension, v 1.0.11.0. I do not see this error when the dependency targets netstandard 2,0 instead.

[rdorta]

+1

[peter-perot]

Any news here? I lifted a project to netstandard 2.1, but now I'm not able to run the t4 text template generator.

[WizX20]

I'm also having this issue with T4 templates.

[sgaliamov]

+1

[androdd]

+1
Adding this <#@ assembly name="netstandard" #> shows me this error:
Running transformation: System.BadImageFormatException: Cannot load a reference assembly for execution.

[drewdelano]

+1

[stason4ik]

+1

[kccarter76]

the templating engine is not resolving, netstandard, Version=2.1.0.0, Culture=neutral, PublicKeyToken=cc7b13ffcd2ddd51

the assembly for version 2.1 is not in the gac., currently .net core 3.x is the only runtime that can use the netstandard 2.1. the assembly can be found in the runtime folders for netcoreapp 3.x.

[duda92]

+1

[appie2go]

+1

[amather]

+1

[pellea]

Any news on that one? Still have the same issue ...

[AKA285066112]

+1

[Nokecy]

+1

[ihatred123x]

same issue. any news? happy new year.

[jlaw74]

Same issue. Any updates. I have two machines running VS 16.8.4. I get this error when attempting to Add-Migration on one of them.

[DenisKudelin]

+1

[ali50m]

+1

[Afischbacher]

Any update here please from the team, it been over 2 years and there is still no fix for this issue and it's forcing people like myself to not be able to use .NET Standard 2.1 due to my dependency and usage of T4 templates.

[terrajobst]

My understanding of T4 is that it runs on .NET Framework. As such, it won't work with .NET Standard 2.1 but should work for .NET Standard 2.0, assuming you run on .NET Framework 4.7.2 or higher, see footnote 2.