It seems to not be able to find the "transformations.lua" file in the "descriptions/ab+" folder. Since the file seems to be missing, i recommend you to reinstall the mod.
This can be done by unsubscribing, starting the game and going into the main menu of any save game. then closing the game and subscribing to the mod again.

I see. When reinstalling previously, I just unsubbed and resubbed to the mod right away, as that worked for other games I've used workshop with. Followed your instructions and it works now. Thanks for the help!