iMac keeps crashing after Catalina upgrade

Yes, have had the same issue since getting my iMac 11/2019 with Catalina.

Big Sur has not fixed the problem, which is intermittent for me, and seems to happen on shutdown/restart with external monitor attached. The specific message in Big Sur is now:

panic(cpu 5 caller 0xffffff7f8c51a3a1): "virtual bool IOAccelLegacyDisplayMachine::display_mode_did_change(uint32_t): vendor driver returns false"@/AppleInternal/BuildRoot/Library/Caches/com.apple.xbs/Sources/IOAcceleratorFamily_kexts/IOAcceleratorFamily-438.7.3/Kext2/IOAccelLegacyDisplayMachine.cpp:267

Has anyone had any joy fixing this, other than replacing the computer? Just want to know if it is indeed a hardware issue...

Thanks!

William

¿Just want to know if it is indeed a hardware issue...?

I am kinda of the opinion that it can't be simply a hardware issue .

Possibly a firmware incompatibility with a wide range of systems hardware configurations wide variety of 2012- 2020 Macs .

I am confident that it is a firmware issue. The problem is that once you update to Catalina you cannot go back in firmware versions even if you downgrade which is why the issue persist even on clean installs of prior OS X. My Mac still crashes and unfortunately was at the cutoff for Big Sur so Catalina is all I've got. Wish I would have never updated as now I feel that I can't even sell my MacBook knowing that it crashes all the time.

I would also note that this is not an issue of incompatibility with other programs—it happened when I first got my iMac with Catalina installed. I reinstalled it, and it kept happening—but intermittently.

Both times it was with no other software installed and no peripheral hardware attached.

How many people has this happened to only with a dual monitor setup?

Exactly the same thing happening on my Macbook pro 2018. With this one seems to happen only when I have external monitor attached to it... very annoying bug...

After doing this https://support.apple.com/en-us/HT201295#t2 I have not suffered this. Computer screen turned of couple of times after this and still all ok.

Keeping my fingers crossed.

Same as this: https://discussions.apple.com/thread/250713766?answerId=251388232022#251388232022

There is a thread at Apple Communities with this same issue at:

https://discussions.apple.com/thread/250715149

here's my kernel panic report if anyone understands it, I don't.

Happens within minutes of opening MS Word.

Some Crash Log details:

Read the article at https://support.apple.com/en-us/HT210220 or google "IOS 13 Reminders Mojave".

You may have selected not to upgrade them.

Additional note: You may have to do a similar task for iMovie, yet the procedure is different and the steps can be found at Apple support page:

If iMovie isn't working on your Mac (HT206157)

Yes, here's the system log immediately after a crash today.

actually just had another crash and was able to get the crash report on it. here you go.

Every time the system goes to sleep it crashes, so a lot of people are preventing their Mac from sleeping. When you think about it, Apple is making the world use more power...