How to fix unresponsive Apple menu and menubaragent in macOS 27?

Part 1 of 2

A couple of things would be useful to establish first.

How many times has the iMac been restarted since upgrading to macOS 27? 

Does this happen only after the iMac has been idle or gone to sleep, or can it also happen during normal use? 

And have you tried starting it in Safe Mode? 

If so, does the problem still occur there? 

Apple notes that Safe Mode can help determine whether software loaded at startup is contributing to a problem.

When the problem occurs and the rest of the Mac is still usable, you can try restarting MenuBarAgent instead of restarting the whole computer. 

Open Terminal with Command–Space and enter: killall -KILL MenuBarAgent

Press Return. 

Some macOS 27 users have reported that this temporarily brings an unresponsive menu bar back. It is a user-reported workaround, rather than an Apple-documented fix.

If the problem comes back, note whether it happens again after the iMac has been idle or after waking from sleep. 

That may help identify the circumstances under which it occurs.

If another application is also unresponsive, Option–Command–Esc opens Force Quit. Apple Support — How to force an app to quit on Mac

If the whole Mac becomes unresponsive and you cannot restart it normally, 

Apple advises holding the power button for up to 10 seconds to turn it off, then pressing it again to start it. Any unsaved work may be lost. Apple Support — How to force an app to quit on Mac

It is also worth checking System Settings > General > Software Update for any available macOS update. 

If the problem continues after restarting, testing Safe Mode and installing any available update, further troubleshooting would be appropriate rather than repeatedly restarting the iMac.

Part 2 of 2 

To avoid a game of 20 questions   

Download the Application Etrecheck  ( External Link ) directly from the Developer.

This is a Diagnostic Tool that makes no changes to the computer.

It makes a coherent and readable inventory of both the Hardware and Software used on the computer 

The application is free or paid for added features. 

The Report will Not Reveal Any Personal Information. 

Post back the Full Report - Share Report >> Copy , then  paste  >>>> using the Additional Text Icon  <<<<

Welcome and thank you for reaching out. 🤗

If you have any antivirus software installed, then remove it A.S.A.P. as they interfere with the system operations and performance.

If you don’t have anything like that installed, then try the following:

First, let’s see if this issue happens in Safe Mode:

1. Shut down your Mac.
2. Press and hold the power button on your Mac. As you continue to hold the power button, your Mac turns on and loads startup options. When you see Options, release the power button.
3. Select your startup disk. It's named Macintosh HD, unless you changed its name.
4. Press and hold the Shift key, then click the “Continue in Safe Mode” button below your startup disk.
5. Log in to your Mac. You might be asked to log in again.

If the strange behaviors do not occur, then it may possibly be a software issue.

If the issue doesn't continue in safe mode:

Leave safe mode by restarting your Mac normally, then try to reproduce the issue.

If the issue doesn't return, it might have been resolved by the other things that safe mode did at startup, such as checking your disk and clearing caches.

If the problem persists, then let’s try this:

• Software Update.
• Use Apple Diagnostics to test your Mac.

Need more help?

• United States: 1-800-APLCARE.
• Contact Support.
• Mac Support.
• Mac User Guide.

Good luck! 👋🏼😉

Smiliñ 😎 Brian | Community Volunteer