So I've been wanting to create a new map, but I cannot get the height map to work. This is a picture of it:

The size is 513x513, it's set to Grayscale, was done in GIMP and exported as a png image into FeralHeart > media > terrains. Usually this would work, but every time I correctly put the name of the image into map maker FeralHeart crashes. I don't want to have to redo it, but fix it somehow instead; thoughts on how I could?