The metal-backed plastic piece has separated as G-Benz said. The plastic rotates around on the pin and causes the window to "hang" from the cable. You need to rotate the plastic piece back into position, drill a little hole and put a sheet metal screw in it to keep it from rotating again.

This probably makes sense to someone who has done it, and I hope it helps when you dig into it and see the parts for yourself.

__________________
D.H.

04 ML500
02 E430

Experience is something you don't get until just after you need it.