Apple Silicon M1 Macs and MacBooks have fallen victim to a bug that forces a screen saver to occupy the screen without warning, preventing users from continuing to work.

According to MacRumors, the problem is specific to Macs and MacBooks with the Apple M1 chip and is caused by a new feature in macOS Big Sur called Fast User Switching. This feature allows users to switch accounts without having to completely log out, but the bug apparently causes the screensaver to render desktop space unusable even though the mouse cursor is still visible, making it impossible to log in or log out at all It is said that this makes it impossible to log in or log out at all.

M1 Mac and MacBook owners report that the screensaver appears randomly, several times a day. Once the screen saver appears, cursors and keystrokes alone cannot move the image as they can with a non-buggy screen saver, and it effectively stops there.

One user on the Apple Community Forum stated that disabling the screensaver prevented the bug from recurring, but many users claim it has no effect.

Fortunately, there is a more reliable way to regain control from the screensaver; one of the most consistently reported solutions for MacBook users is to close and open the lid to return to the login page. The same result can be achieved by lightly pressing the Power/Touch ID button or by pressing the Alt, Command, and Q keys together.

Affected users can also disable the fast user switching feature altogether. Obviously, none of these solutions are truly ideal. They must either interrupt themselves to return to the login page or disable a new and potentially useful software feature. Hopefully Apple is aware of this problem and is working on a more permanent fix.