I just upgraded to VS2019 and am unable to build an existing solution. The Compiler generates the following error on some of the projects within the solution:
The "DisableSdkPath" parameter is not supported by the "Csc" task. Verify the parameter exists on the task, and it is a settable public instance property.
Check if you are using the Microsoft.Net.Compilers package. Upgrading to Version 3.0.0 resolved the issue on my side.