So i needed a custom pathing texture. (Great shout-out to Dr. Boom for teaching me this: http://www.hiveworkshop.com/forums/tutorial-submission-283/pathing-everything-about-154558/) I have created a texture using GIMP 2 and saved it as .tga. It is listed in the importing manager, but it fails to load the texture and buildings have no pathing whatsoever – units walk trough them and other buildings can be built in them.