After the installation of update KB5012643 for Windows 11, users found a new bug while using save mode.

If you want to use safe mode in Windows 11 by pressing F4, you will be confronted with a flashing screen that makes everything unworkable.

There is a simple method to avoid this problem from happening. Instead of using F4 while booting into save mode, you need to press the option F5, including network drivers.

Save Mode
Save Mode

While using this method, everything should work just fine. Microsoft is aware of the new problem, and as always will come up with a fix at a later date.

More on this: here