Just had a look a the files and sorry I cant see anything obvious, it doesnt like it its the rivers. All I could think of to do is to get a clean file and introduce errors one by one and try and simulate the crash, then you might identify what file is causing it. Good luck
Also, the map looks amazing, I didnt realise you had extended it wll the way through north Africa and down the east coast to Zanzibar.
With the topology, have a look at this >
website<, the second image from the bottom. You can use transparency tools to copy and past sections of the topology from this map onto your topology map. You then need to resize and pivot, all achievable using GIMP. It works really well and look pretty good in game compared to hand drawn work.