When I try to rename materials, they keep giving themselves prefixes which are breaking my model ingame! How do I stop blender from doing this? e.g I'm trying to rename etkc.003 to etkc, but then other 'etkc.00x's are renaming themselves!
This happens if you already have a material named that way. Since two materials cannot have the same name, Blender will put a .001 at the end, or .002 if that already exists, and so on.
How do I fix this, by making blender use the same material? It's screwing up the textures (no texture, full white texture, etc.)
Press the button besides the name. you should get a drop down menu where you can select the correct material.