I had this problem with the latest upgrade and had to go here for a fix.
Windows 11’s latest preview release appears to be causing a whole host of serious problems for several users, including unresponsive Start Menu, Taskbar, Explorer.exe, Windows Settings, and other critical bits of the operating system seemingly disappearing or broken.
This is happening to those who have installed Windows 11 Build 22000.176 or Build 22449, which are the latest round of preview updates for Beta and Dev channel respectively. There is a range of different issues reported by testers on the Feedback Hub and our forum, but it appears that the tech giant has rolled out a server-side fix.
At the moment, it’s not clear how widespread these Start Menu and taskbar gremlins in the operating system might be. In some cases, users are reporting that the Taskbar and Start menu are totally blank, and an hourglass is displayed when users move the cursor closer to the taskbar.
“In the new version, after startup, the taskbar disappears. After restart, the machine runs slowly and the taskbar is stuck. Repeated restarts are still invalid, any software can not be operated, and some shortcut keys are invalid,” a user noted in the Feedback Hub and there are similar complaints on our forum.