Schema composer automation broken in v12.1

[Geert Bellekens]

I'm writing (or trying to anyway) an add-in to extend the Schema Composer.
I checked the documentation (after I finally found it), and Rodrigo's example, but for some reason I couldn't get the import formats to appear when pressing the Generate button.

After trying the the SC Addin example from the program files folder, and the example downloaded from Rodrigo's site I saw that both of them didn't work either.

I rolled back from v12.1.1225 to 21.1.1224 but still no luck.
After rolling back to v 12.0.1214 it started working again.

I'll report it as a bug. I must say I'm off to a very bad start for the first day on my new project 

Geert