Occasionally when I am looking through the civilopedia my game will crash and I will have to restart. I mostly play the Conquests, so maybe their civilopedia is less reliable?
Also, I do make custom units(but don't mod the civilopedia, I don't know how to) in these scenarios. However, I do not import any new images or unit animations. I just do things like adjust attack and defense and this particular time it crashed while I was playing Napoleonic Europe and gave the Prussians an Elite infantry(a clone of Lifeguard but renamed), in case this has something to do with it.
Also, I do make custom units(but don't mod the civilopedia, I don't know how to) in these scenarios. However, I do not import any new images or unit animations. I just do things like adjust attack and defense and this particular time it crashed while I was playing Napoleonic Europe and gave the Prussians an Elite infantry(a clone of Lifeguard but renamed), in case this has something to do with it.