Scaffolding: Add support for .NET Core 3.0 on --version 3.1.1

[rmed1na]

Currently there is not support for .NET Core 3.0 on version 3.1.1 neither 3.0.0.

Steps to reproduce: Try to install this package on .NET Core 3.0 framework

Expected behavior: Success

Actual behavior: Error. Platform not supported

Additional information about the project being scaffolded, such as:

Target framework(s): .NET Core 3.0

Package version of Microsoft.AspNetCore.App or Microsoft.AspNetCore.All (if applicable):

Package version of Microsoft.VisualStudio.Web.CodeGeneration.Design - this may be added to your project by scaffolding:

[deepchoudhery]

We expect the version of the code generation package to match the project tfm. You may install the 3.0.0 using --version 3.0.0

[rmed1na]

We expect the version of the code generation package to match the project tfm. You may install the 3.0.0 using --version 3.0.0

Already did. Version 3.0.0 doesn't work either.

[deepchoudhery]

I see. What is the version of your global tool?

[rmed1na]

You mean dotnet --version? It was on 3.0. Upgraded yesterday to 3.1.101

[deepchoudhery]

Are you using the cli tool or on Visual Studio?

[rmed1na]

Tried both. Same result on either of them.

[deepchoudhery]

For the cli, the tool might've been updated.
Use dotnet tool uninstall -g dotnet-aspnet-codegenerator, then dotnet tool install -g dotnet-aspnet-codegenerator --version="3.0.0"
Run your scaffolding scenario after that and let me know.