Hello.
I've already completely uninstalled and reinstalled SteamVR.
I'm in the summit house, but as soon as I start a game like Rec Room, The Lab, etc., it loads, and then the picture goes black, and it pops up on the monitor:
"A critical error has occurred with STeamVR.
I have reinstalled SteamVR, still.
But I can easily start external games.
For example, "Beat Saber Old Build", which was recently available for free download.
Windows itself has just been installed fresh for a few days, virtually nothing else than the VR stuff, Opera and 7z.