I was having the same issue and the reason was, one of my nuget package was referencing Microsoft.Extensions.Configuration.Abstractions Version=8.0.0.0 and I was able to fix the issue by downgrading this nuget package to an older version which used Microsoft.Extensions.Configuration.Abstractions Version=6.0.0.0. Please note that referencing the nuget package which used 7.0.0.0 also did not work.