GetPathsOfAllDirectoriesAbove() cannot be evaluated after updating .Net Framework version (4.6.2 to 4.7.2)

Question

A project I have been working on was upgraded from .NET Framework 4.6.2 to 4.7.2. On build, in a file that is not my code, I get the following error:

I also

Answer 1

This happned to me when I updated Microsoft.Net.Compilers in an old project. Removing Microsoft.Net.Compilers completely, and then updating Microsoft.CodeDom.Providers.DotNetCompilerPlatform resolved my problem.