Macbook Air M1Source: Daniel Bader / iMore

What you need to know

  • Many M1 Mac users are reporting issues with Fast User Switching which leaves them unable to dismiss their screensaver.
  • The only apparent fix so far is to disable the feature.

A new M1 Mac bug is leaving many users unable to dismiss their screensavers when trying to use Fast User Switching.

As reported by MacRumors:

A growing number of user reports online suggest some of Apple's M1 Mac models are susceptible to a Fast User Switching bug that spontaneously activates the screensaver and leaves the user unable to dismiss it.

Based on posts in the MacRumors forums, Apple Community forums, and on Reddit, however, a screensaver can sometimes take over the screen of Apple Silicon Macs without notice, rendering the desktop workspace completely unavailable.

While the screensaver appears on the screen, the mouse pointer is still on top and moving, but nothing else works, and users have to close and re-open the lid on their MacBook Air or MacBook Pro, or light press the Power/Touch ID key or use the Alt-Command-Q key combination to get back to the login page.

The report highlights forum posts and Apple support threads showing users unable to exit their screensaver whilst using Fast User Switching. As noted, some have found closing and opening the lid of their Mac to work, although one user had to use Remote Access from a different device to get around the issue.

The only sure-fire fix seems to be disabling Fast User Switching, however, this is obviously very inconvenient for users who want to use this feature. The problem has been reported on all three of Apple's M1-based Macs running macOS Big Sur.