Terrain Alpha Mask Help!

[jash1]

I've made a Terrain Mask but for some reason it won't work.
It's in RGB colour,in FeralHeart/media/terrains, its a Png. Everytime I type it in, Caps and all and with .Png on it  and I press enter in Feralheart and it doesn't do anything...No sign telling me its wrong or crashing... My Terrain map works fine, the mask just doesnt. Please help!
Thanks.

[Ingredient]

After typing it in try changing the ground texture, it might help show if the mask is really there or not. When making the mask make sure you are using the right colours, Red, Green and Blue.

Are you making a terrain mask for the first time? Maybe try following a video

GIMP part 1

GIMP part 2

Photoshop part 1

Photoshop part 2

[_-Rain-_]

Is it the right size? It should be 513 x 513 pixels.