As the title says, I'm on my way to creating a completely new map, just to learn the basics. Being new to map modding I'm having both alot of fun and alot of trouble succeeding. The newest error I've encountered is the following:

Symptom: KTM's with message on exit: 'Script error in .../descr_strat.txt, at line xxx, column x. You have chosen an invalid tile(0,0)for the settlement of
If line xxx is the bottom of the descr_strat file and the settlement name is not specified. Line xxx is indeed at the bottom of descr_strat.

As far as I can tell, I don't have any non-specified pixel colours. All I've got is 21 regions, sea and settlements, totaling 23 unique colours according to Irfanview.

The cause doesn't seem to be the one stated as the most common, and being a novice at this I have no idea on how to proceed. A hint at what to look at would be great, if anyone has a clue.