iMac keeps crashing after Catalina upgrade

I too had the same issues with the RAM though I have not been able to get the Apple RAM and OWC RAM to work together. Separately they work great, but together I get crashing and processor issues.

I did test with Geekbench and Novabench, both showed that with both the Apple RAM and OWC RAM the processor ran much slower.

Im currently running with just the OWC RAM.

I have found a remarkably simple workaround for this problem. Like everyone else, my MacBook Pro crashes with eternal monitors after 1 -3 minutes of sitting idle. From what i have found, this is due to USB to HDMI (DVI, SVGA, etc) adapters and docking stations going to sleep or low power mode after a few minutes of static content. So, simply change the Desktop Background to change every minute so the adapters do not go to sleep. Trivial and simple, but so far seems to work on my system. Please note: you must set this to one minute on every monitor and not just your primary. System Preferences -> Desktop & Screen Saver, Desktop (tab), change picture [every minute].

this has worked beautifully for an hour for me now (my late 2012 iMac with nothing else attached) was crashing every 10 mins before, even with screensavers & energy saving off. Oddly, my 2013 MacBook Air hasn't crashed once, both with same Catalina update. Nice one!

It appears that Catalina not only has updated to 64bit native but also the drivers have too. Noticed the BT one has been updated from Mojave and is the root issue why some of the BT devices (eg WM1000-XM3) are pairing intermittently - the suppliers have not changed anything. Reading this and other similar posts, Apple have massively goofed up.

Looks like my iMac saw it through - it knows what we're trying to do, i.e. prevent it from crashing. It continues to crash. The wallpaper changing trick didn't fool mine at all. I'm back to typing or moving the mouse frantically when waiting for a build to compile or just letting it reboot periodically.

[Edited by Moderator]

Yeah the mod was funny, had to read twice what I wrote ;)

Well, I've got a 128GB OWC RAM and other than that I've got two external monitors connected via USB-C and an Apple USB-C to DisplayPort adapter. Maybe it's one of these at fault but I've been using these for years.

Apple perhaps need to use TimeMachine, go back in time and revert all their code to how it was a few months ago. Problem solved.

Similar issue with my 2017 iMac, video card Radeon Pro 560 4 GB (not sure if that qualifies for pro Vega). Particularly I'm experiencing failures when computer wakes up from sleep: external USB3 drive (Lacie) gets ejected improperly and bluetooth keyboard/mouse lose connectivity (not sure what comes first, if the bluetooth or the HD ejection) and everything freezes. But I also often have the message the computer restarted due to a problem. Maybe those are different issues but still symptoms of a poor working of Catalina (Mojave was much more stable). One thing that I noticed is that below* processes are blocking my external hard drive even if I do not have explicitly any application running (these background processes start by themselves a few minutes after launch of OS). This has been going on since after Catalina. In short: 1) not able to eject my external HD, 2) computer freezing after wakeup with loss of bluetooth connectivity, 3) sudden restarts during sleep.

*

photolibraryd

cloudphotod

com.apple.medialibraryservice

Looks like some magic has happened since last Friday, this *same* crash with timeout has not occurred and I do have now all usual power savings on.

BUT, now I'm suffering things like keyboard and trackpad are lost (internal ones), no content on screen and only way to recover is to power the thing off and back on. And these usually happens when no external monitor attached...

Had few calls to AppleCare and sent them few times the logs, but looks like they don't really have a clue what is happening.

Very very frustrating... Lucky for me the computer mostly works so I can still do normal daily tasks and now shutting it down everytime I move from office to home or for a night.

Oh, the thing I did on Friday: repaired Photos library as I noticed a lot of activity against medialibrary when it crashed.

iMac late 2012, 8GB. No external monitors. Printer hub on USB. Installed 10.15 fresh (Cmd-R reboot) with no difference. Continues to crash and reboot upon shutdown.

panic(cpu 1 caller 0xffffff7f832ebaae): watchdog timeout: no checkins from watchdogd in 187 seconds (601 totalcheckins since monitoring last enabled), shutdown in progress

mine is crashing too, but only when using Light Room. Its fine if I do one operation, but if I try to do 2 operations lets say start 2nd folder export it pegs the processors and will crash computer. 27' i9 with 2tb ssd, 40 gig 2667 ram, and pro Vega 48

Hi,

with my MacBook Pro (2016, no modifications, no external monitor)I had the same experience the last days. It lasted the whole day, with many Safari Tabs open. However, at the end of the day, when I suddenly do something else (one one day I was researching for a presentation, so many Safari Tabs, one or two preview documents and Keynote, all fine, then after I was done, I started to write emails and the crashes started again) I experience usually a small series of crashes and then it stops.

I have to admit, I have not been heavily using my laptop since the crash series started, so I might have triggered the problem less often. Anyway, it is very annoying, since it is not really related to any particular activity or app. Apple must have received >30 crash reports by now (I did not sent all, since sometimes the crash happened before I had a chance to read and hit the send button).

Cheers

Duc

go back to mojave's tho thedisktool panel if you have an Time Machine backup try to use that but the extension may have been alter then backup for backup file change the extension then use it from the boot system worked for me

This thing is nasty. I was experiencing crashes with my two external screens connected, but over time my Mac Book Pro (13") apparently started to heal itself and now it even feels stable... I was disconnecting my screens every time I needed to leave my desk and lock the screen - but since about 3 days, I am leaving everything as it is and it does not crash anymore.

Similar issue experienced on my iMac 21" Late 2012 with right after upgrade to Mac OS X 10.15 (19A602). NVRAM reset helped for me (Command-Option-P-R ). Tried it first because 1) was lazy to reinstall Catalina 2) in the last panic report was:

...

Event:            Sleep Wake Failure

...

IMO direct hint on HW/NVRAM issue.

By today so far so good