How to avoid M1 Mac’s dreaded screensaver bug


Avoid M1 Mac's screensaver bug
Fast User Switching seems to be the problem.
Photo: Apple/Cult of Mac

A strange bug plaguing a seemingly large number of M1 Mac owners spontaneously displays a screensaver that cannot be dismissed. But there is an easy way to avoid the problem until Apple rolls out a proper fix.

We’ll show you how.

Owning an M1 Mac has been a largely positive experience for most. The latest MacBook Air, MacBook Pro, and Mac mini are significantly faster than their predecessors, despite running cooler and quieter at all times.

But the new machines do appear to have some teething problems. The latest, which appears to be a simple macOS bug, renders machines unusable after they get stuck inside a screensaver.

The problem seems to be connected to Apple’s new Fast User Switching feature in macOS Big Sur. Fortunately, there is a workaround that prevents it for now.

M1 Mac suffers spontaneous screensaver bug

The bug causes a screensaver to appear, even when the machine is actively being used, then prevents it from being deactivated. Reports suggest it affects all M1 Mac machines, and all versions of Big Sur.

“I was actively editing some Calendar entries when all of a sudden the same exact thing happened (screensaver on, user locked out),” explained one user, running macOS 11.1, in the MacRumors forum.

“I ended up using Remote Access from my MBP to get in and log out the user on the Mini. The ‌Mac mini‌ then jumped to the login screen and it’s working fine again now. Very weird.”

Another user, running macOS 11.0.1, said they’re experiencing the same issue on two separate M1 machines. “Happens a few times a day while actively using the computer,” they added.

How to avoid it

There is no proper fix for this problem just yet; we’ll have to wait for Apple to address it in a future macOS Big Sur update. In the meantime, however, there are a couple of things you can do to get around it.

The first, which only applies to MacBook Air and MacBook Pro, is to close and then reopen your machine when you get stuck at the screensaver. This is the only way (that we know of right now) to return to your desktop.

The other fix, which works on all M1 machines, is to disable Fast User Switching temporarily. It’s a pain if you’ve come to rely on this feature, but it’s the only thing that really works for now. These are the steps to follow:

  1. Open System Preferences on your Mac.
  2. Click Users & Groups, then select Login Options.
  3. Click the padlock to unlock this menu, then enter your password.
  4. Disable Show fast user switching menu.
  5. Return to System Preferences.
  6. Click Dock & Menu Bar, then select Fast User Switching.
  7. Ensure Show in Menu Bar and Show in Control Center are disabled.

This should prevent spontaneous screensavers that you cannot close. We’re hoping Apple rolls out a proper fix that allows Fast User Switching to be enabled without any issues soon.