问题
After installing .net 5.0 dotnet-cli works, but after creating new project dotnet build fails with error error MSB3644: The reference assemblies for framework “.NETFramework,Version=v5.0” were not found.
回答1:
Make sure the environment variable MSBuildSdksPath equals <dotnet install path>\sdk\5.0.100-preview.3.20216.6\Sdks
来源：https://stackoverflow.com/questions/61745089/msb3644-error-when-building-with-net-5-0