I've just played through a huge battle and it crashes as soon as I click to close the battle summary scroll to return to the campaign map.
There is no certain way to fix this, but there are currently three ways that I know of that are reported to minimize or eliminate them.

* Leave the battle summary open for 10-15 seconds instead of closing it right away.
* Replace <RTW>/EB/data/world/.../map_regions.tga with <RTW>/corrected_regions.tga. Delete map.rwm and do not use the trivial script to start EB the next time around. After quitting EB again, copy the newly generated map.rwm file into sp game backup.
* Try the suggestion of Theages in this thread.
My CTD is similar to this one, although it only affects one specific faction and only when the script is activet. I shall return to the game now and try not to save right before the battles and see if it improves stability...