Crash whenever I exit specific cell

[Osteoporozis]

I've just gotten to the end of the Shivering Isles main quest; now, after defeating Jyggalag, my game crashes whenever I leave the cell. Any cell at all; I have tried all accessible from the palace area. Disabling all mods did not fix the problem.

Thanks in advance for any help.

[Osteoporozis]

Searching the internet I found someone (on Gamefaqs, of all places) with an identical problem; the thread talked about solving the problem with console codes in the end.

Restarting that particular quest did nothing; neither does finishing the quest via console commands. To be honest, I've run out of ideas. Until I find a solution I'm playing on from another save.