I have no earthly idea why but Visual Studio will not allow me to create a functioning .edmx file.
I’ve tried to recreate the file multiple times, following the UI prompts each time, but all I get is this cryptic error message that reads:

An error occurred while initializing the frame's content System.Runtime.InteropServices.COMException (0x8000000A): The data necessary to complete this operation is not yet available. (Exception from HRESULT: 0x8000000A).

This usually works without issue. There’s no reason in the code that this should not work.
This is something outside the code but I’m not sure.

I’ve tried recreating the file multiple times and even waited over the weekend to see if the issue would just go away but it hasn’t. No we’re blocked on development efforts until this is resolved.