Sunroof gets stuck and makes a loud clicking/popping/snapping sound as the open/close button is pressed. This happened a number of years ago and estimates to fix/replace were in the thousands of dollars, so I unscrewed the window from the frame to find that a plastic piece attached to the track had broken in two. I was able to glue it back together, thoroughly clean the frame, apply white lithium grease, screw the window back on, and run the sunroof again.

I'm having the same stuck sunroof issue again and it's likely that the grease has dried out or gunked up with dirt/debris. I rarely run it anymore after the first time it broke down.