5th turn CTD

[uanime5]

I've made a mod and discovered a strange bug. The mod will CTD at the start of the 5th turn no matter what faction you are, what you do, or how long each turn is (such as 1 or 2 years).

What could be causing this and how can I fix it?

[alpaca]

What kind of mod is it? You have to give some specific information about what you changed to be able to notice something.
You could also generate a trace log and see what happens before the ctd.

[uanime5]

I've fixed this problem. It was caused by a trying to exclude a culture from the religion starter trait.