Pre update saves slow and laggy

[Aztepol]

Since the Undead update my pre update saves now runs slow and jumpy. New saves work fine so seems only old saves are effected. Was playing the save the day before and it was working great so I suspect the update had something to do with it.

Hasn't been fixed in the recent update either.

 

[Aztepol]

The game ran perfectly before the Undead update, even with 1000+ prisons and 500 staff.