Screensaver comes on randomly and prevents use in Big Sur and M1

I have filed a bug report on screensaver issue and just finished a call with Apple support. They have provided a solution and it did worked for me. Screensaver didn't show up yet. My machine is "MacBook Pro (13-inch, M1, 2020)".

Issue below command by launching Terminal app (Finder -> Applications -> Utilities -> Terminal) from your admin login account. Please make sure to type as shown below as these commands are case sensitive.

sudo defaults write /Library/Preferences/com.apple.screensaver loginWindowIdleTime 0

sudo defaults write /Library/Preferences/com.apple.screensaver loginWindowIdleTime 0

Issue above command (provided by Apple support) by launching Terminal app (Finder -> Applications -> Utilities -> Terminal) from your admin login account. Please make sure to type exactly as shown above as these commands are case sensitive.

It did fixed my screensaver issue and I am good until I get it addressed by SW Update. I have also filed a OS bug report about this and Apple is aware of this and hopeful they are going to address this on a future release. Apple acknowledged this is not HW related.

My machine is "MacBook Pro (13-inch, M1, 2020)".

I had no issue exchanging my MacBook Pro within the 14 day return window. However, the issue still occurs on the new one. Until I disabled “fast switch user”. I no longer have the issue after disabling that. Apparently Apple is aware of the issue and will resolve it on the next OS update. Also It is reported to not be a hardware issue, it’s software.

A user, Pemby, posted a fix that solved the issue for me. (I'm using a headless 2020 M1 Mini on Big Sur 11.2.3).

"

I think I found the solution. I noticed an energy saver plist with a UID appended to it.

/Library/Preferences/com.apple.PowerManagement.{UID}.plist

In addition to the default

/Library/Preferences/com.apple.PowerManagement.plist

Reading the default plist with my correct system settings gave me

{

"AC Power" = {

"Automatic Restart On Power Loss" = 1;

DarkWakeBackgroundTasks = 1;

"Disk Sleep Timer" = 10;

"Display Sleep Timer" = 0;

"System Sleep Timer" = 0;

"Wake On LAN" = 1;

};

SystemPowerSettings = {

"Update DarkWakeBG Setting" = 1;

};

}

Reading the plist with the UID gave me

{

"AC Power" = {

PrioritizeNetworkReachabilityOverSleep = 0;

"Sleep On Power Button" = 1;

"Standby Enabled" = 0;

TCPKeepAlivePref = 1;

TTYSPreventSleep = 1;

};

}

So I added the `"System Sleep Timer" = 0 and "Display Sleep Timer" 0` by the following linesp.

sudo defaults write /Library/Preferences/com.apple.PowerManagement.{UID}.plist "AC Power" -dict-add "System Sleep Timer" 0

sudo defaults write /Library/Preferences/com.apple.PowerManagement.{UID}.plist "AC Power" -dict-add "Display Sleep Timer" 0

"

Same issue for me 3x so far on MacBook Pro M1 with Big Sur 11.0.1. One of my 2 Fast Switch accounts had the screen saver enabled. Have disabled that so hopefully will not happen again.

Helpful tip on other forum was do Cmd+Shift+Q then Enter. Will log you out so quicker than rebooting!!

I think I’ve mentioned in one of my posts after testing that indeed this issue occurs regardless of the fact two users are/are not logged in.

fast user switching being enabled is causing it.

Once I disabled it - I haven’t seen the issue for few days.

the obvious drawback is the need to logout one user before the other can log in, so really need to make a choice what is more inconvenient for you until (hopefully;-)) this is fixed.

Check whether the menu for "fast user switching" is enabled (independent on whether you use fast user switching or not). I disabled it, and so far I didn't have the issue again.

Configuration / Users & Groups / Login Options / uncheck the item "Show fast user switching menu as..."

I have found that setting a hot corner to turn the display off works as a workaround. If the screensaver comes on, I pop the cursor in that corner, wait for the display to turn off, and bring the cursor out of that corner - the display turns back on and the screensaver is gone. No need to shut the lid.

In case diabling fast user switching does not solve your issue, here my "ealier workaround":

Previously (when "ScreenGate" still occurred on my M1 macMini) I set a hot corner: I activated "Put Display to sleep" on my lower left corner. When "ScreenGate" occurred, I moved my mouse to the lower left corner, the display went to sleep and with a key stroke the machine was running again.

Although my lower left corner is still active, I don't need it anymore, as disabling fast user switching made "ScreenGate" not appear anymore on my machine... I hope this might help until Apple brings a fix.

rgt12, until Apple will bring a fix, you have two choices: a) either disable fast user switching (should make the issue disappear) but you have to completely logout so another family member can log in. or b) enable a hot corner with „put display to sleep“ and when the anemone appears, move mouse to the hot corner. With a keystroke youre back in. This hot corner has basically the same effect as closing the lid.

Disable 'Fast user switching' on both accounts manually.

Uncheck the box + Remove it from control center too.

Do this on both account.

Remove it from menu bar on both as well.

This worked for me on a mac mini m1.

<< Apple should be repairing this. >>

According to reports just above yours, this is fixed in MacOS 11.2 released recently. Be sure you have updated!

Brand new MBP and this issue started in my third week. Tried everything with no success. Closed and reopened the lid in frustration and everything was back to normal. It’s happened multiple times since with the open and close clearing the issue up. Frustrating though.

After I tried couple of things, with unresponsive screen saver still showing up, I have a quick and dirty solution. I just closed my MBP screen, waited a sec, and pulled it back up. I didn't have to enter my login and the screen saver is gone. I miss my SJ

[Edited by Moderator]

After running the following command in a terminal :

sudo defaults write /Library/Preferences/com.apple.screensaver loginWindowIdleTime 0

I don't have the issue anymore.

I even set a screensaver in both user session I have on my Mac mini and it seems that the problem is gone so far...

Very encouraging.