I decided to try making my very first map mod. Unfortunately I ran into this error:
I’ve been searching through the forums trying to find a fix, but it looks like this problem has been around for years.
Did anybody ever figure out how to fix it?
I’ve got it working! At last!
This is what I’ve tried so far. I found this info on the forum, so I tried this first:
Just out of curiosity, where did you extract game files to? I had a similar issue where nothing I did would make the region show up. Turns out I extracted the game files to my “Working” directory…which Editor doesn’t seem to like. Which makes sense because Editor looks for all game files in a specific location (Grim Dawn installation directory) and if its not there, bad things happen.
So I copied all the extracted database\records from my ‘Working’ folder to the installation folder. But sadly, that didn’t work.
So then I came across this:
Ok after some more trial and error I finally got the Map Editor to work. I had to not only extract the game files to the games install directory but I had to set my Working and Build folders in Asset Manager to the games install directory as well.
So the Working, Build, and Tools directories have to be set to the games install directory in Asset Manager and the game files have to be extracted to the games install directory as well.
So I did all that and voila! It worked!
It seems, when setting up Asset Manager for the first time, that you should leave the directories at their defaults (which is the installation directory).
My trouble was that I followed an old tutorial that told me to extract the files to a folder called ‘Working’. That’s what messed everything up 
Ah well! At least I’ve got it working. I figured I’d leave this here just in case anybody else runs into this problem.
Good luck.