Panic: Watchdog Timeout, Happens on Shutdown

I have the same vintage Mac Mini with a 1 TB hard disk and had the same problem. Here is what I did and some observations.

(1) On September 25, I performed a Mojave update (10.14.5 to 10.14.6). Afterward, the computer was very slow. It took two minutes for a pull down menu to come down.

(2) I called Apple Support and after some diagnostics, we decided to install Catalina using Option-Command-R without erasing any volumes. After that, the computer would not shut down normally and would reboot after a “panic: watchdog time-out”. What I noticed is that I would be able to shut down normally right after the reboot. However, after some time, something will do something to the system so that if I run “First Aid” using Disk Utility, it will trigger a warning (“Spaceman main free count 218039846 dos not match sum of free counts 218126044”, the numbers change each time). As long as the warning is absent, I can shut down normally.

(3) I called Apple Support on September 30, and we reinstalled Catalina using Command-R. The shut down problem continued and some applications would not respond. At this stage, the computer did not verify an application before opening it. That is supposed to be a Catalina feature.

(4) I did a timemachine full backup on October 11 and called Apple Support on Oct 12, the Tech Support person walked me through the followings:

(a) sign off Apple ID

(b) shut down

(c) Use Command-R to get to MacOS utilities (I am already in 10.15.7)

(d) Use disk utility to erase two volumes (“Macintosh HD data” first, and then “Macintosh HD”)

(e) Install MacOS 10.15.7.

(f) Use timemachine backup to restore data

(5) Previous to erasing the volumes, the disk has 5 volumes with 2 mounted. After the installation, it has 6 volumes with three mounted. There was an additional “Macintosh HD data”. I started seeing the computer verifying some of the applications. However, the shut down problem still persisted.

(6) On October 13, I decided to repeat steps I did on Oct 12, but erase the disk instead of the volumes. This link (https://support.apple.com/en-us/HT208496) explains the difference. I erased the disk and left it in Mac OS Extended (Journaled) format, and let the Catalina installer reformat the disk to APFS . I was back to 5 volumes on the disk, the 2 mounted volumes (“Macintosh HD data” and “Macintosh HD”) and three others (VM (virtual memory?), and 2 “not mounted”).

(7) The normal shut down failed on the evening of Oct 13, but has been working the last 2 nights. Now, it verifies an application before opening it for the first time. I have not seen any “spaceman” warning when running First Aid.

(8) One final thing. When the machine boots up after the installation, there seems to be a lot of house keeping activities. It would be best to leave it alone for an hour of two rather than start opening applications to test things out.

It may be too soon to declare victory. I will let you know.

This marks one week of trouble free operation. Since my computer did not shut down normally on Oct 13, I counted Oct 14 is the first day of normal operation. During this first week, I shut down the computer each evening. There has been no “spaceman” warning when I ran First Aid and no panic reboot when I shut down. Please note that I use the computer at home, mainly using the browser, and occasionally open up Excel or Word files.

Some observations:

(1) The “verification” window showed up the first time I opened Word, Excel and Powerpoint (Microsoft Office 2016) and Acrobet reader. They opened without “verification” after that.

(2) My Photo library is on the Mini’s internal hard drive. It is less than 15 GB. The first time I opened Photo, it did a restore. It opened normally after that.

(3) The printer and scanner settings were preserved and things work as before.

(4) Downloaded files using Browser.

If you want to follow the procedure, I think it is worthwhile to get on Apple Support and have someone walk you through part of the way.

On getting a full backup. I did not used my old Time Machine backup because I excluded some files and did not do automatic backup. The last partial backup was done under Mojave. To start a full backup on a new drive, I connected the new drive and went to Time Machine in System Preference and turned off automatic backup. I also removed all the exclusions (click the “option” button). I then clicked “add or remove backup disk”, and chose the drive I wanted to use. It then asked which drive (the old one or the new one) I want to continue using or both. I chose “both”, and it said that it will alternate between the 2 drives. I then clicked backup now and that started the full back up.

I do not plan to post any more comment unless something goes wrong. I will monitor the discussion thread to see if there are questions for me.

I am sorry to report that the problem returned on Oct 22.

Each day, the “spaceman” would show up when I run First Aid. It would not shut down normally at the end of the day. While the “spaceman” warning was present, I had trouble opening certain Excel and Word files (Excel/Word not responding and I have to force quit), but some others just open fine. I think the files themselves are OK because I can use Numbers and Pages to open them. It always the same few files that won’t open.

Here are a few things I have tried:

(1) uninstalled Norton Symantec End Point Protection

(2) removed 32-bit apps

(3) cleared the Excel and Word “recent files” lists

(4) Updated Firefox to 82.0.2

I plan to call Apple support soon and will report if I make any progress.

I called Apple support on Oct 30 and was transferred to a senior advisor. The advisor helped me delete some old applications, downloaded a free malware to check and set a Genius Bar appointment for Nov 2. On Nov 2, a took the Mini in and they run diagnostic for about 20 minutes. Nothing was found. They suggested that I leave the Mini so that they can erase the disk and reinstall Catalina and run further hardware and software diagnostics. It would take 5 - 7 days. After that, I should attempt to manually rebuild the user files rather than using TimeMachine to transfer all the files. I was not ready to leave the computer at that point, so I took it home.

After I got home on Nov 2, the “spaceman” warning appeared. Since everything else was working, I left the computer on between Nov 2 and Nov 6. On Nov 6, some applications started to “not responding” and I have to shut down. The watchdog panic reboot occurred.

While trying to decide whether to get a replacement Mini or a MacBook before I turn in my old mini, two things happened this week. Apple announced the new Mini with the M1 chip, and the release of Big Sur. I decided to limp along a bit longer and see what happens.

I have the same issue on M1: https://forums.macrumors.com/threads/constant-kernel-panics-userspace-watchdog-timeout-no-successful-checkins-from-com-apple-windowserver.2222878/post-29345367

I wouldn't hold your breath on this issue.

Thanks to JohnAlanWoods for the tip about M1. I will have to decide whether to use time-machine to transfer files to my new Mac Mini if/when I get one.

Since my last post, I continued to have the watchdog panic problem, but can avoid it if I use safeboot. Also, I upgraded to Catalina 10.15.7 on Dec 31. The machine retarted with regular boot and have not seen a "spaceman" warning yet. Of course, the "honeymoon" lasted 1 week last time.

I will give another update in 2 weeks.

Things went fine after Dec 31 a long as I did not shut down the machine. I shut down the machine on Jan 8. The problems (Space Manager warning and apps started hanging) returned after I restarted on Jan 9. Typically, it will work OK for about a day after reboot. I have been using safe boot when I can.

I am considering whether to update to Big Sur. David, could you let us know if you are still good with Big Sur?