Some M1 Macs Affected By Fast User Switching Screensaver Bug
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.

In macOS Big Sur, Fast User Switching allows users to quickly switch between user accounts without having to completely log out. 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.
MacRumors forum member drmacnut:
Brand new Mac mini M1, 2nd day using it, Big Sur macOS 11.1 (20C69) with screensaver and screen sleep set to 20 mins. I was actively editing some Calendar entries when all of a sudden the same exact thing happened (screensaver on, user locked out). 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.
Apple Community forums member Squeaks2369:
I am experiencing the same issue. M1 MacBook Air. Big Sur 11.0.1. Happens on two separate user accounts, both with the screensaver disabled. No way to exit the screensaver but to close then open the lid. Happens a few times a day while actively using the computer. Browsing various forums it appears others are having this issue as well.
Video shared by MacRumors forum member dawideksl Disabling Fast User Switching prevents the issue from happening, but that obviously leaves the login feature inaccessible. Having the screensaver disabled in System Preferences for all users doesn't seem to make a difference either.
The issue has been reported on M1 MacBook Air, M1 13-inch MacBook Pro, and M1 Mac mini models, and occurs on all versions of macOS Big Sur, including the latest 11.1 update. Affected users are advised to submit feedback to Apple to hopefully facilitate a fix.
(Thanks, Chris!)
Popular Stories
If you have been experiencing issues with wireless CarPlay in your vehicle lately, it was likely due to a software bug that has now been fixed.
Apple released iOS 18.4.1 today, and the update's release notes say it "addresses a rare issue that prevents wireless CarPlay connection in certain vehicles."
If wireless CarPlay was acting up for you, updating your iPhone to iOS 18.4.1 should...
Apple is preparing a "bold" new iPhone Pro model for the iPhone's 20th anniversary in 2027, according to Bloomberg's Mark Gurman. As part of what's being described as a "major shake-up," Apple is said to be developing a design that makes more extensive use of glass – and this could point directly to the display itself.
Here's the case for Apple releasing a truly all-screen iPhone with no...
The first iOS 19 beta is less than two months away, and there are already a handful of new features that are expected with the update.
Apple should release the first iOS 19 beta to developers immediately following the WWDC 2025 keynote, which is scheduled for Monday, June 9. Following beta testing, the update should be released to the general public in September.
Below, we recap the key...
Despite being more than two years old, Apple's AirPods Pro 2 still dominate the premium wireless‑earbud space, thanks to a potent mix of top‑tier audio, class‑leading noise cancellation, and Apple's habit of delivering major new features through software updates. With AirPods Pro 3 widely expected to arrive in 2025, prospective buyers now face a familiar dilemma: snap up the proven...
While the iPhone 17 Pro and iPhone 17 Pro Max are not expected to launch until September, there are already plenty of rumors about the devices.
Subscribe to the MacRumors YouTube channel for more videos.
Below, we recap key changes rumored for the iPhone 17 Pro models as of April 2025:
Aluminum frame: iPhone 17 Pro models are rumored to have an aluminum frame, whereas the iPhone 15 Pro and ...
Apple's iPhone development roadmap runs several years into the future and the company is continually working with suppliers on several successive iPhone models simultaneously, which is why we often get rumored features months ahead of launch. The iPhone 17 series is no different, and we already have a good idea of what to expect from Apple's 2025 smartphone lineup.
If you skipped the iPhone...
Apple today released iOS 18.4.1 and iPadOS 18.4.1, minor updates to the iOS 18 and iPadOS 18 operating systems that came out last September. iOS 18.4.1 and iPadOS 18.4.1 come two weeks after the launch of iOS 18.4 and iPadOS 18.4.
The new software can be downloaded on eligible iPhones and iPads over-the-air by going to Settings > General > Software Update.
There have been complaints about ...
Apple today released tvOS 18.4.1, a minor update to the tvOS 18 operating system that came out last September. tvOS 18.4.1 comes two weeks after Apple released tvOS 18.4, and it is available for the Apple TV 4K and Apple TV HD models.
tvOS 18.4.1 can be downloaded using the Settings app on the Apple TV. Open up Settings and go to System > Software Update to get the new software....
Apple has quite a few security features that it's added to iPhones, iPads, and Macs over the years. Now more than ever, it's important to make sure you're taking advantage of the built-in security tools that are available to keep yourself and your data safe, so we've rounded up a list of the most important options.
If you don't already have these enabled, you might want to consider turning...