No need to be sorry! We're all here to help ya~
To be clear, when you say terrian mask, you're reffering to the red green and blue colored picture that determines what the ground texture is, right?
In that case:
-Is the file the correct size?
-Is it in RGB mode
-Are you changing the terrain types? (The default is this black texture, so you simply have to change it to the desired type.
-Are you positive your typing the file in correctly?
