[ART] How to make heightmaps?

[Mudbill]

I don't know of the issue you're having with your editors, but it sounds to me you have some bigger issues, possibly with your computer's drivers being buggy or corrupt, or the installation missing some files. If you got the game on Steam, I suggest verifying your files and then redownload the editors and overwrite them. Also update drivers if possible.

As for the file size, it's probably just how your files are compressed. Shouldn't be an issue.