I had also a problem where the game crashed when I entered the WB very recently. When you enter the WB, all tiles will be revealed and the game will render all tiles. It is likely that the crashed is caused because the game couldn't render certain elements on the map. This explains why it doesn't crash before you entered the WB, because the bugged thing didn't have to be rendered yet.
For me, it was an error in ArtDefinesBonus.xml, I had a bonus which path to the kfm file was wrong.
The problem can also occur in basically all elements visible on the map. (units, improvements, bonus etc.) You should check every preplaced unit, bonus, improvement etc. if that causes the crash. The easiest way is to start from an empty world and placed every unit, bonus, improvent etc. until it crashes. This is the thing you have to investigate.