New declensions can't be created (bug)

[Mymokol]

In my project, I found that I'm unable to create new declensions in the Part of Speech section. I'm unsure as to what lead to this or how to reproduce the bug, sadly.

When I click + button in the Conjugations/Declensions Setup screen in the left column, the window saying it will deprecate all existing declensions appears, and when I click Yes, it doesn't create a new declension, if I'd already set up autogeneration for the existing declensions in that Part of Speech. That is, for example, if I have a verb PoS, and have already set up some autogen rules for them, the Conj./Decl. Setup screen won't let me make any new Declensions.

What's noteworthy is that this only occurs in one project of mine. I tried copying the project and saving it as a new one, but the error still persisted. When I made a new project just to test out the bug, I couldn't reproduce it.

Here are some screenshots of the actions taken in the problematic project, in order:

(clicked + in the bottom left) (clicked Yes)

[DraqueT]

Thank you for the detailed writeup! Could you please post the language file here or send me a copy at draquemail@gmail.com?

[Mymokol]

Sure! I'm sending it to the email.