Solution has compiled successfully, but after I added an existing class file to the project, this error appeared:
The specified task executable \"csc.exe\
In my case I could go from Microsoft.Net.Compilers 2.4.0 to Microsoft.Net.Compilers 2.10.0. No need to use Microsoft.Net.Compilers 2.8.2.
Microsoft.Net.Compilers 2.4.0
Microsoft.Net.Compilers 2.10.0
Microsoft.Net.Compilers 2.8.2