rebooting continuously - Monterey 12.3.1

Since it does not happen in Safe Mode that would indicate that something that is loaded during normal operation but not Safe mode is causing the problem. You have two option:

1. Have you tried booting to Recovery and reinstalling macOS that is offered in Recovery:

How to reinstall macOS - Apple Support

Then restore from backup but only restore your user, not setting or apps and other stuff since it appears one of those is cause the problem. After that redownload the apps you need . I would do that incrementally and restart in between to know if one of the apps is causing the problem.

2 When in Safe Mode download and run this app so we can find more information about your installation.

https://etrecheck.com/upgrade

It shows what is launched and other information and is very useful in finding causes of problems. After you first launch the app make sure you check Enable full disk access in the box in lower left.

After running the app use the app's Share feature “Copy” that pastes to clipboard. Then paste it in the text box for a reply in this forum click on the addition text icon. This is because the normal reply text box limits how much you can type.

Paste additional text box image

No personal identifiable information is contained if the app output. The app was written for a person who is contributor to these Apple Support Communities. This may show the cause of the problem but is harder since you have to do this is Safe Mode.

1 - Suggest restarting in Safe Mode. This will perform a Disk Repair, clear cache files and only load Apple Software, extensions and fonts. The boot up will be slow and can take some time - Normal.

2 - Sometimes a Safe Boot followed by a Normal Boot will just put things right.

3 - Does the issue present in this mode ?

4 - If not - there could be something in the main User Account playing up. To further isolate this - Set up users, guests, and groups on Mac. Then log out of the Main User account and log into the dummy account and test again if the issue persists.

5 - If the issue is present in the dummy account - then, this appears to be a System Wide issue on the computer.

6 - If after performing each of the above steps is the order that have been presents  and still have issues - please advise for possible further assistance.

7- Suggest downloading the Application Etrecheck directly from a well Respected ASC Contributor. And Safe to use.

The application is free or paid from added features. 

Run the application with Full Disc Access ( Security & Privacy - Full Disc Access ).

It will take a Snap Shot -  both the hardware and software.

 The Report will Not Reveal Any Personal Information. 

We can have a look at the report for possible issues and may have possible suggestions to resolve the issues.

Any Third Party Applications that will interfere with the normal operation of the OS, alter, modify, remove or delete or attempt to do so is an invitation for disaster .

It may require a Reinstallation of the OS in-order to replace any modified, altered, removed or corrupted elements of the OS this software has inflicted on this computer 

Although some or all of these Applications maybe or may not be available on the Apple Apps Store, it does not mean Apple has verified what exactly the Application can do, does do or is doing to the Computer. That responsibility is left to the User to perform their due diligence on the Application before purchasing and installing it.

Any of the below should be removed as per Developers Instructions 

This will include CleanMyMac , This will include BitDefender , 

This will included Norton Antivirus , Sophos Av Software

Intego AntiVirus, McAfee, MacKeeper, Avast AntiVirus

Ad Guard, Webroot

The The Built in Security  is all that is required.

Update:

Booted into 'recovery' mode.

Did a first-aid disk check.

The Data volume had a message of a some 'repair'. (Unfortunately I did not copy it)

Rebooted and its now it has been 2 days of running OK...

Hope my nightmare is over...

Normally would say Avast and Little Snitch was the root cause.

But this @Barney-15E has identified from the Panic Report a Hardware Failure - would tend to agree.

Time for a visit to an Apple Authorized Service Provider or Genius at an Apple Store for evaluation or repairs.

doronby55 wrote:

Since it runs perfectly on the second user, I am not at all sure its 'hardware failure'.

I have not posted a crash report yet as the last two failures were frozen machine and nothing new in showed up in 'Console'.

Kernel panics are predominantly caused by third-party kernal extensions and hardware faults. There are some other rare causes, so it could be one of those. If you choose to rule out the kernel extensions you have installed then that likely leaves it to be a hardware fault.

I would agree that it working on one account but not the other tends to exclude a hardware fault. That then implies a kernel extension problem.

The panic log would indicate whether either of those are loaded at the time of the panic.

You can uninstall the software to see if it continues to panic or not. A past version of little snitch did cause kernel panics, and avast has always caused kernel panics. It is completely useless, also.

That's a stackshot. Got a kernel panic log?

Probably avast, could be little snitch.

Do you have a panic log to post?

No third-part kexts, so quite possibly a hardware problem. Take it to an Apple Store Genius Bar or Authorized Repair center for evaluation.

Above are EtreCheckPro reports.

Clean boot into 'good user' and run EtreCheckPro then clean boot into 'bad user' and run EtreCheckPro...

'Bad user' also Reboots in 'Safe Mode' after 30-120 minutes.

Thanks.

Mine (Retina 5K, 27-inch, Late 2015) keeps rebooting under one user but runs fine under the 2nd user account I created.

No apps are loaded at startup.

Sometime the reboot is after 1-2 hours of use. Even in safe mode...

Not sure what to do next.

2nd reboot this AM....:(

FYI: Both accounts ('bad' and 'good') use Avast and Little snitch. (they have both been running for years...)

panic log ? do you mean the 'console' crash report ?

If yes, I will wait for the next 'reboot' and send it.

Thanks!

Since it runs perfectly on the second user, I am not at all sure its 'hardware failure'.

I have not posted a crash report yet as the last two failures were frozen machine and nothing new in showed up in 'Console'.

Etrecheck Report for the " Good User "

Problem: Computer is restarting

Description: 

2nd user is ok. First user = restarting

Major Issues:

Time Machine backup out-of-date - The last Time Machine backup is over 10 days old.

Suggest running the TM Backup more often

Minor Issues:

 Unsigned files - There are unsigned software files installed. These files could be old, incompatible, and cause problems. They should be reviewed.

Self explanatory

 Runaway user process - A user process is using a large percentage of your CPU.

Hardware Information:

  iMac (Retina 5K, 27-inch, Late 2015)

 Drives:

  disk0 - APPLE HDD ST1000DM003 1.00 TB (Mechanical - 7200 RPM) 

  Internal SATA 3 Gigabit Serial ATA

  disk2 - Samsung SSD 870 EVO 2.00 TB

  External USB 5 Gbit/s USB

    disk2s1 - EFI (MS-DOS FAT32) [EFI] 210 MB

    disk2s2 [APFS Container] 2.00 TB

      disk3 [APFS Virtual drive] 2.00 TB (Shared by 6 volumes)

        disk3s1 - B**************  - Data (APFS) [APFS Virtual drive] (Shared - 900.34 GB used)

        disk3s2 - Preboot (APFS) [APFS Preboot] (Shared - 356 MB used)

        disk3s3 - Recovery (APFS) [Recovery] (Shared - 1.11 GB used)

        disk3s4 - VM (APFS) [APFS VM] (Shared - 1 MB used)

        disk3s5 (APFS) [APFS Container] (Shared - 15.19 GB used)

          disk3s5s1 - B************B (APFS) [APFS Snapshot] (Shared - 15.19 GB used)

        disk3s6 - Update (APFS) (Shared - 2 MB used)

Here I need more Eyes on this one.

Seems the user may / may not be running the OS or some Applications directly Off the External Drive ?

Mounted Volumes:

  disk1s1 - M************************)

    1000.00 GB (Shared - 708.77 GB used, 266.52 GB available, 266.31 GB free)

    APFS

    Mount point: /Volumes/M************************)

disk1s5 - Macintosh HD

    1000.00 GB (Shared - 11.21 GB used, 266.31 GB free)

    APFS

    Mount point: /Volumes/Macintosh HD

    Read-only: Yes

  disk3s1 - B**************  - Data [APFS Virtual drive]

    2.00 TB (Shared - 900.34 GB used, 1.16 TB available, 1.08 TB free)

    APFS

    Mount point: /System/Volumes/Data

  disk3s2 - Preboot [APFS Preboot]

    2.00 TB (Shared - 356 MB used, 1.08 TB free)

    APFS

    Mount point: /System/Volumes/Preboot

  disk3s4 - VM [APFS VM]

    2.00 TB (Shared - 1 MB used, 1.08 TB free)

    APFS

    Mount point: /System/Volumes/VM

  disk3s5s1 - B************B [APFS Snapshot]

    2.00 TB (Shared - 15.19 GB used, 1.16 TB available, 1.08 TB free)

    APFS

    Mount point: /

    Read-only: Yes

  disk3s6 - Update

    2.00 TB (Shared - 2 MB used, 1.08 TB free)

    APFS

    Mount point: /System/Volumes/Update

Antivirus software: Apple and Avast

Already covered

System Extensions:

  [Running] Little Snitch Network Extension - version 5.4.1 (Objective Development Software GmbH - 2022-05-02)

    [Running] Avast Antivirus System Extension - version 6.3.139 (AVAST Software a.s. - 2022-05-04)

Already covered

  Software Installs (past 60 days):

    2022-04-10 SYS_PC_Tool_setup_mac_6.26 (0)

Refer to below image.

Say OS X 10.8 Minimum - there is a lot of to Time and macOS Versions between then and Now macOS 12