It turns out there were migrations that had been applied in the versions between ours and target version (11.4).
We identified those and copied the migrations into our project and it successfully compiled and is partially working.
I've had good results with Wijmo controls. Not cheap, but worth it for my project.
Yes thanks, I've been using that method you suggested.
This basically reduces IRepository to an IQueryable using EF Core.
I gotta say, after a few projects trying to put a repository abstraction on top of EF, I'm not a fan of this abstraction... Could someone please explain why it is necessary in this framework?