Increasingly frequent crashes at random points, only happens on campaign map

I will just be playing totally fine and then I will get an "unspecified error". Usually this is when I click a button in a scroll or something, but it hasn't ever happened during a battle, even a large battle, only on the campaign map.

Here's an error log: system.log.rar

Memory leak, a known M2TW problem. The longer your session is, the bigger the draw on RAM and the more likely this sort of error is to occur.

Firstly, for regular play change your error logging method from "trace" to "error". Secondly, there are some other methods to improve the game's use of memory that you can research.