Technical issues with Heroes III.

Hello. My problem is related to the ResEdit program. I wanted to use it to fix a bug so that Naga banks would give gems instead of sulfur. I downloaded a modified crbanks.txt file from another website, which should fix the bug after it is added to the bitmap.lod archive. I added it there using this program, and then something strange started happening: first, the game wouldn't start at all, complaining that a certain regions.txt file was missing. I would send a screenshot of the error, but it disappeared after another upload of the crbanks.txt file. The game starts, but after clicking the "Scenario" button, it crashes every time. Campaigns work. Please tell me where I went wrong and how to make the game work.