The retractable Plisse screen door has an inside and outside channel the door handle is fastened into. I had a problem where the inside handle would slide down the track to the floor. I had to use a piece of electrical tape to hold up the handle so it could be used.
In looking at the outside handle it looked like it had a fastener of some type holding the handle in place but no such fastener on the inside.
I contacted Plisse via their web site and learned there is a set screw in each handle and it takes a very very tiny allen wrench (hex key) to keep the set screw tight. In my case the inside handle was missing this set screw and the outside handle was loose and about to suffer the same fate.
Plisse is sending me a new handle, set screw and wrench to fix my missing one. GREAT quick customer service.
This is just an FYI for those with the newer Plisse screen doors on their Scamps to check the set screws before they fall out. (or only your dog will appreciate the new handle at floor level when it slides down.)