Node + Game engine = Problem (viewport is file, GLSL)

Ive got this really weird problem.
I have a material setup, used for a game project of mine.
Basically, it uses vertex colors to determine where which material goes.
Here it is:
But running ingame it looks like this:
Selecting other UV-maps leads to disappearing materials.
What am I doing wrong?
Urgent, kinda :spin:

I don’t know, but I would recommend baking your texture as diffuse and normal maps. It generally is faster and more efficient.

Well, with HUGE terrains thats gonna be a big problem.
I need this to work