I'm trying to do my first blending. I patch a non blend texture terrain, copy it with ctrl c -ctrl v, and add a blend texture at the second.
All is good and i can blend and see what i'm doing but when i put a light i can see only the non blend terrain. I ensure myself that the blend one is up and that it's not inverted. If i try to pull up the blended one the light shows me it, but if i turn match it with the non blend one it disappear. Help me please 

In the editor with light preview it wont show some blends but it will show textures like decal ivy.
Ingame it will look good.
Prob just a way to save memory in radiant.

Oh ok. I was going mad. Thank you so much