The holes aren’t drilled properly.  This made it impossible to screw parts together. This happened I two areas. In one area the holes weren’t aligned. In the other, the hole was too small and the screws doesn’t fit.  Luckily, there were three ither screws that fastened, so we had to leave one empty.  There’s also a hole drilled  in the frame that doesn’t require a screw. Looks bad