Crashing when pressing end turn.

Hi.

Both empire(modded) and napoleon(vanilla) seem to work fine. But at times they both crash when I press end turn. When trying to load the autosave it also crashes. This is quite annoying since I am quite bad at manually saving, leaving me with a crashed campaign. This seems to be same issue. (Shogun 2 works fine)

Is there any usual reason for this? Any fix?

Other than how well ETW and NTW are not optimized, not much. Corrupted savegames are nothing new. The only real way to minimize it is massive amounts of free disc space and shut down everything not game related while playing.