iMac 2017 Restart - Kernel Panic - Userspace Watchdog Timeout

Hi sopobo,

Thanks for posting in Apple Support Communities.

To address your Mac experiencing kernel panics, start by making sure all macOS updates are installed. This will include latest performance enahancements.

1. From the Apple menu  in the corner of your screen:

*Choose System Settings. Then click General in the sidebar, and Software Update on the right.

*Or choose System Preferences. Then click Software Update.

2. If Software Update finds new software, click the Update Now or Upgrade Now button to install it.

3. Enter your administrator password, if asked. During installation, your Mac might restart, and you might see a progress bar or blank screen several times.

Update macOS on Mac - Apple Support

*If your Mac suspects that a particular app caused the restart, it might ask whether you would like to move the app to the Trash. Click Move to Trash, then contact the software developer to see if a software update is available.

*Use safe mode to try to isolate the cause of the issue.

*Reinstall macOS. If the issue continues after reinstalling macOS, check your hardware.

These and additional steps can be found in If your Mac restarted because of a problem - Apple Support

Regards.

Uninstall the Avira anti-virus software by following the developer's instructions. Anti-virus apps, cleaning/optimizer apps, and third party security software are not needed on a Mac and usually causes more problems than they solve, plus they impact system performance. If you still have problems after uninstalling Avira, then run EtreCheck again and post the new report here.

macOS already has great built-in security which is further enhanced by the user practicing safe computing habits as described in this excellent article written by a respected forum contributor:

Effective defenses against malware and other threats - Apple Community

It appears you are booting from an external USB3 Samsung Portable T5 SSD running macOS 12.6 Monterey.

While CCleaner is not running when you ran EtreCheck, you should also unisntall this app as well. CCleaner was acquired by Avast anti-virus some years back and from my understanding, Avast has destroyed this app. Besides these types of apps usually cause more problems than they solve. I don't believe CCleaner is causing the problem here.

Run DriveDx and check the health of the iMac's internal hard drive. It is likely the internal hard drive is failing and perhaps its failure has gotten severe enough that it is affecting performance even while booted to external media. Post the complete DriveDx text report here using the "Additional Text" icon which looks like a piece of paper. You may also want to do the same for the Samsung SSD as well, although this will require installing a special USB driver.

After getting the internal drive's health report, you can try unmounting or ejecting the internal drive to see if it makes any difference (not sure what happens if the Mac wakes up from sleep).

Also disconnect all other unnecessary external devices just in case one of them is causing a problem.

If you power off or reboot the system, then try running the online Apple Diagnostics (disconnect all external drives). If the diagnostics have issues booting, then the internal drive is likely especially if you have access to another Mac to compare it.

sopobo wrote:

there is no Samsung software running, I have checked

Actually in the second posting of the second EtreCheck report the Samsung driver is shown as loaded, but the original second posting of the EtreCheck report does not have the Samsung driver listed at all. You must have posted the wrong report when you thought the second report was not uploaded correctly...the forums here are having some issues with downloading reports because the website is corrupting the upload...they can be read if users wait long enough.

I disconnected everything except the external boot drive of course

I have disabled one drive and dropbox and I have updated to the last Monterey version and the same thing happened while restarting over and over again - about 5-6 times until it finally opened - and over an hour time

Have you uninstalled CCleaner?

it seems to me that when I unmount or eject the internal drive it starts a little better but the internal drive mounts again by itself and usually it says that cannot unmount because it runs some applications and busy, although I do not start anything on it

Can you boot to the internal drive? If so, what OS is on it? How does the iMac work while booted to the internal drive besides a bit slow since it has just a slow hard drive? You may want to try it twice, once with no external drives connected and once with the external boot drive connected so see how the OS on the internal drive handles the external drive. If the issue only occurs while booted to the external drive, then the external drive may be the problem. Or maybe Avira or something else caused an issue with macOS which still remains so that you may need to reinstall macOS.

Run Disk Utility First Aid on the hidden Container on both the internal drive and the external boot drive. Within Disk Utility you may need to click "View" and select "Show All Devices" so that the hidden Container appears on the left pane of Disk Utility. Even if First Aid says everything is "Ok", click "Show Details" and scroll back through the report to see if any unfixed errors are detected. If the boot drive has unfixed errors, then you can first try running First Aid from Internet Recovery Mode to see if the errors are fixed. Otherwise, If any unfixed errors are listed, then the drive will need to be erased, reinstall macOS (if the boot drive), then restored from a backup.

As a last resort before reinstalling macOS, try disabling Spotlight indexing first on the internal drive, then on the external boot drive. To do this you need to go to the Spotlight System Preferences and add the volume to the exclusion list in the Spotlight "Privacy" tab. I don't recall whether indexing will be on or off on the internal drive if you disable Spotlight indexing on the internal drive while booted from the external. I think it will be disabled since it writes a special flag to the drive to indicate the indexing state and is not just a setting on the one OS.

Can you boot the Apple Diagnostics? This can be informative as well depending on how good your Internet connection is because I'm mainly interested in how the iMac boots, but having the diagnostic results is a bonus.

The health report for the internal hard drive appears good with nothing to suggest a problem.

Reviewing the EtreCheck report again, I do see a Samsung item running even though the rest of the Samsung driver software was not running at the time of the report. I would uninstall the Samsung software since it should not be needed especially since you are using it as a macOS boot drive.

Try disconnecting all other external devices in case one of them is causing a problem.

You are also at least one update behind on macOS updates for Monterey. Maybe the problem is fixed with a later macOS update patch.

I wonder if One Drive or Drop Box could be causing a problem. You may want to temporarily disable them.

Another test can be to boot from a Knoppix Linux USB stick to see how well this boots and how it works compared to booting from macOS. By default Knoppix does not mount any drives. Download the Knoppix DVD .iso file with "EN" in the name for ENglish. Use the .iso file as a source for Etcher (Mac/Windows/Linux) which will create the bootable Knoppix USB stick. macOS won't be able to mount the Knoppix USB after it is created which is normal. Option Boot the Knoppix USB stick and select the orange icon labeled "EFI". The Mac may appear frozen on the Apple boot picker menu while Knoppix is booting so make sure to give Knoppix lots of time to finish booting. This may take even longer for your iMac since it already has booting issues.

Once Knoppix boots to the desktop, see how well the computer works to see whether you notice any problems. I haven't really used Knoppix v9.x yet, so I don't know if it is possible to easily mount any APFS volumes using the File Manager (I doubt it since the process to access an APFS volume from Linux is a bit complicated), but you should be able to browse the Internet and launch apps such as LibreOffice or GIMP, etc. although there are a lot of other apps which are more technical and won't be of any use here. Firefox is fairly locked down and may not be able to access a lot of sites, but Chromium should work better IIRC.

You may also want to check the health of the external SSD. You can either do this from macOS by running DriveDX, but this requires installing a special USB driver in order to properly communicate with the external drive to access its health information. Or you can access the external drive's health information while booted to Knoppix. Just click the Knoppix "Start" menu and navigate the menus to "System Tools --> GSmartControl". Within the GSmartControl app, double-click the appropriate drive icon to access the drive's health report. You can see the health report with the "View Output" button or you can save the report to a text file using the "Save As" button. At least checking the health of both drives using Knoppix may allow you to tell if this type of access to each drive shows up with any slow downs or longer wait times. Not quite as good as reading the drive, but still may reveal a clue.

I'm really curious how well the system boots and works when booting to the internal drive and even a Knoppix USB stick. Usually if Knoppix has issues booting, then it indicates some sort of hardware issue. Again you may want to test with & without the external SSD attached to compare.