I have created an object and drew the texture on it, it worked and still works fine. Then I created another island, created and assigned another texture to it. However, Texture Paint mode doesn't work for it! I can draw only on the left side, on the texture itself, but not on the object... How can I solve it?
before you do anything check your blend mode in 3d view by pressing n > Tool > brush setting > blend mode and set it to mix
1) check if object is selected first
2) isolate object before painting by pressing num/ or ~ to toggle local view
4) try saving your image before doing the actual painting then save blender file then go File > Revert and see if the issue still exist. 5) if all else fails just go to edit mode and press ctrl+shift+n to recalculate normals and try again painting it.