Sketchup (2021 Pro) won't start anymore - projects open in a blank white screen

[TDahl]

Here is a recently reply from @colin to another topic with some Windows 10 keyboard sequences that might help locate or move some window:

Sketchup locks and bongs at me in W10

When you get into the state where you are being bonged at, do this: Alt-spacebar, then release both keys. Tap the M key (for Move, tap a different key for other languages). Tap any arrow key. Move the cursor. The lost window should be attached to the cursor.