I feel guilty asking a question like this around here, but I\'m at a loss and would appreciate some help.
A proof-of-concept like web application was built on one PC
My project was built with .Net Core 2.2 but I had .Net core 3.0 preview installed. I uninstalled .Net Core 3.0 from my system and went through all my class libraries, removing Microsoft.Net.Compilers 3.0, then rebuilt and it worked.