I was having this issue and couldn't figure out what was going on. It seems I had some custom content conflicting with custom traits. I tested all folders (I have mine sorted clothes, hair, furniture etc.) and took traits out and it ran fine. Removing the rodent cage didn't break my game and seems to have stopped the standing queue. (When this was going on my game wouldn't pause or let me switch between characters. Also MCCOMMAND told me something was conflicting all of a sudden when adding clothes and accessories I thought were fine.) I had the traits in well before the new clothes I added, so I guess two were fighting and just one of them needed to be removed. I decided to just remove the traits (was only a few haha).
Not sure if this will work for you but my game is running okay now. Hope it helps! Otherwise I have noooo idea and can only assume it's an EA script error that only few are encountering. Or if it's just triggered by certain mods. Whatever the issue my game seems (only have run it for a few minutes but I can pause and switch characters, no MCCOMMAND notification that a file was broken.) to be going good.
