The main structural rail and wall mount clip are clever.  Got lucky with these holes- went through grout. Unlucky that stationary screw happened to line up gap between two studs. Had to use the plastic anchor.  We think there was to much weight on the rail and the door continuosly rolled open even though level showed absolutely level.  We ended putting a small piece of duct tape on top rail just enough to provide slight resiostance for one roller tehn it stayed closed.