First, I've done everything properly as far as I know. I do have grayscale, 513x513 picture, and I have it saved as a MapnameTerrain.png I have searched the forums but all of the answers are the same and nothing seems to help. I have tried copying the map onto a new file, but it doesn't work either.
My only guess is the fact that GIMP wont save a file as .png, so you have to export it as one, but even that changes nothing.
Anyone know what's wrong?