Notification center hangs in macOS Big Sur

Same here. There's a small thread on reddit on the topic https://www.reddit.com/r/MacOS/comments/jtnclh/notification_centre_keeps_freezing/. A reinstall of the Big Sur didn't fix it, nor did the safe mode boot... For me it freezes typically while expanding a stack of notifications.

Hello, for what it's worth. I also use Magnet and Bartender 4 and have talked to the dev teams for those apps and they recommended disabling Screen Time from widgets and that seems to have worked for me. After evaluating the Activity Monitor log, getting stuck drawing a graph. I have been running both Magnet and Bartender 4 for a week now with no issues. Hope that helps.

dobby007 wrote:

After I installed macOS Big Sur on my MacBook the all-new Notification Center started to hang often. It just doesn't open (either by using the Touchpad or by clicking on the clock in the menu bar) and consumes 100% CPU in the Activity Monitor. The only way I can get it fixed and opened again is by terminating the process called Notification Centre :

https://discussions.apple.com/content/attachment/bfe1ab9e-d4f5-4cf4-b3ba-accc6cfa941d

After that it restarts automatically and starts to work normally again. I noticed that it happens also when I try to click on the Clear all button at top right corner of a notification group. Looks like a critical bug to me and seems impossible that Apple missed it during testing (but it seems they really did). Does anyone else have the same problem? If it happens only for me then I want to understand the reason behind it (obviously it's associated with configuration).

Rebooting several times after a major upgrade can sort issues.

You can force quit from there—

or from the Terminal.app copy and paste:

killall NotificationCenter

You can reboot into SafeBoot https://support.apple.com/en-us/HT201262

Takes noticeable longer to get to the login screen, does a 5-15 minute disk repair before it fully boots up, and certain system caches get cleared and rebuilt, including dynamic loader cache, etc. Login and test. Reboot as normal and test as caches get rebuilt.

In Safe mode third party system modifications and system accelerations are disabled, it removes malware, etc hampering smooth operation, however a reboot will put it back to normal mode.

and test.

If your issue continues reinstall the macOS on top of your current macOS to sort anomalies like yours

How to reinstall macOS from macOS Recovery - https://support.apple.com/en-us/HT204904

This works, but then the problem recurs later, after I have responded to a dozen or so prompts about allowing various apps access to notfications. It is not consistent which app might be triggering the presumably corrupt preference file.

Stop using Bartender 4, it is causing the bug. In Bartender 4, uncheck "Open at login" and make sure it is not in your Login items under System Preferences > Users & Groups > Login Items. I also trashed the plist file for notification center, rebooted, and now the 100% CPU notification center bug is gone.

Thanks for the path. Another user said he found the app that caused his freeze that's called Tiles. I know that app and I use Mosaic, they are window manager apps. Mosaic was the app that caused the freeze on my system. Big Sur 11.1. Getting there!

Similar to those who have had issues with window-resizing apps, I have found that Magnet was causing problems for me. I've found that quitting the app and running the terminal command:

killall NotificationCenter

causes the notification center to work properly. Historically, if I open Magnet again, the problem starts within 20-120 minutes, but if I do not use the app then no problems with Notification Center occurred.

It happens when I clicked on a grouped notifications. Even it is a safari notification, it will freeze the notification center. It works till half of the day after restarting the MacOS. It is pretty the same timing with I start having lagging issues when I'm switching between desktops.

Edit: It is fixed when I removed the Screen Time widget. The issue gets back immediately when I add the screen time widget.

MacBook Pro (16-inch, 2019)

2.4 GHz 8-Core Intel Core i9

32 GB 2667 MHz DDR4

Intel UHD Graphics 630 1536 MB

macOS Big Sur 11.2.1 (20D74)

Seeing the same issue high CPU in NotificationCenter often after bringing up list of notifications. Related symptom is panic shutting down if this is occurring.

I followed your advice as a circumvention and so far no recurrence. I don't need most notifications but I need a stable system.

I turned off everything except FaceTime, Family (OSX), Reminders, Safari, SmartCard Pairing in Notification Center Settings.

MBP Intel 16 running latest Big Sur 11.2.3

I'm not sure what you mean by "disabling Screen Time from widgets". Screen Time isn't enabled on my Macbook.

edit:

Nevermind I found it. There is a widget called "Screen Time" and you need to remove that widget.

I had this issue too and I fixed it by completely resetting my user profile's Notification Center preferences. To do that, delete ~/Library/Preferences/com.apple.ncprefs.plist then restart your Mac.

I haven't personally had this problem. Please contact Apple and submit this to them.

Product Feedback - Apple

My solution to this was:

1. disable all notifications from non-Apple apps
2. `killall NotificationCenter` to restart
3. whitelist until you find the culprit