This is not a duplicate of MCL-11992. Although this issue does involve a grey screen frozen launcher, it has a different cause and different effects.

Last night my Windows 10 PC went through an update. I was able to open the minecraft launcher just fine, however today after the update, the Minecraft launcher freezes on a grey screen. Closing it makes it so it will not open again, as there is still one process running in Task Manager after closing which needs to be ended before the launcher will reopen. I have tried removing launcher_msa_credentials.json and that hasn't worked. I have tried disabling high memory programs as some people say it is an issue with assets loading, and that hasn't worked either. Not sure what, but something in the new windows update has broken the Minecraft Launcher. I have gone back to a previous version of windows in the meantime.

Before you group this in with MCL-11992, this is a different issue. That one was opened in 2019 and is resolved. If you are going to group this in with MCL-11992 for it also being a grey screen bug, please remove it from the resolved list as it clearly isn't resolved.

EDIT: over half an hour of waiting on the launcher to load later (and shortly after this bug report was made), it finally loaded everything. I guess the windows update has just caused the loading times for the launcher to skyrocket. Still an issue, as I had to mess with it for the past one and a half hours to get it to work, but not as bad as once thought.