Map Maker: Mask Issues

[DraconisFantasy]

 Hello everyone,

 A friend of mine is currently working on a single layer map mask, and it keeps giving off a glowing effect; despite it not being a 6-layer mask. She and I tried to figure it out, but we ran out of ideas. It only appears to glow in areas that are blurred, which is very strange, and it's something I have never experienced before.

 Has anyone had this problem before? If so, have you been able to solve it?

Things we've tried:

 1. She has tried coloring the blurred area black but had no success.

 2. She has deleted the map mask and re-exported it. This held no success.

 3. She has deleted the height map in-game and re-typed it. Still nothing.

 4. Screaming very loudly. If only.

[Likuu]

Maybe try changing it between jpg and png and see if that does anything to help, if not, instead of using the "blur" tool, use the "smudge" tool and see if that may make a difference at all?

[DraconisFantasy]

 We tried what you suggested Likuu, but unfortunately that did not solve our problem. Thank you for your time and the suggestion though, we appreciate it.

[Oddonelynx]

Is it using layers?

[cytofin]

Would you be able to post a screenshot of what it looks like?
I used to make height maps and masks for a little bit, and remember it glowing when the mask itself
was off by a few numbers.
Red: 255, 0, 0
Green: 0, 255, 0
Blue: 0, 0, 255
If one of those numbers are off, it will cause certain areas to glow on the terrain, especially where
the colors meet.