I am having no luck using the landscape features in UE4. Whenever I paint the heightmap or landscape textures I get black blocks and other artifacts that do not go away after rebuilding lighting. Also, the cursor appears under the terrain and the whole process is quite buggy and not usable at all. (Sometimes the terrain heights will just not adjust, sometimes the painting has no effect at all). I am using UE 4.7.3. I have tried building the most basic materials, using starter content materials and I am now using the advanced display landscape materials from the market place and I am quite stuck at this point. Any help here?