Materials tray difficulty

I was working with the materials tray but now it’s disappeared and when I go and select my tray it doesn’t open, I can’t see it and have tried everything. Any advice?

I think your “sketchUp version” is 2021.
Your “operating system” would be Windows(t10 etc.) or Mac (OS10.xxxx etc.). Please update your profile.
For this advice it would probably help to know what kind of computer “Operating System” you have SketchUp on.

Do you have multiple monitors connected to the computer, or did you have additional monitor(s) connected recently which are now disconnected? I wonder if the missing tray is off-screen somewhere.