iMac keeps crashing after Catalina upgrade

My MacBook air 2018 8GB 128GB hasn't crashed even once in last 1 and 1/2 years. After Catalina upgrade it started crashing and each time I sent the log. Now even the system doesn't even come up. At night if it crash it boots up only in the morning. I tried all hardboot options available. This is the first time experience for me, but killing me...

macOS Catalina upgrade still crashing during startup after installing 19 October 2019 update patch. We have the same problem on two 2012 iMacs, a 2015 MacBook Pro and a 2017 Mac Mini. What was Apple thinking?!

I'm on the supplementary version and it crashes randomly even when I've disabled the screensaver / system sleep and everything else related to idle timeouts. Very, very annoying! I'm usually in the middle of writing code and it reboots, disrupting my momentum and flow as well as any unsaved changes. Aaaaarrrgghh.

What helped me was starting the computer in safe mode, removing all drives etc attached.

Restarted in regular mode see if it works correctly before attaching anything back to it.

If it works, then connect them, one at the time, checking if the computer keeps working correctly every time you connect one back.

I had two external drives, starting in safe mode, fixed the issue for me.

Well.... the panic attacks returned to my Macbook Pro!

panic(cpu 3 caller 0xffffff80090e0683): "m_copydata: invalid mbuf chain 0xffffff81fbb4e700 [off 0, len 12885]"@/BuildRoot/Library/Caches/com.apple.xbs/Sources/xnu/xnu-6153.11.26/bsd/kern/uipc_mbuf.c:5374

For the time being I'm naming my computer "Macbook Amateur".

I must say... over the last years Apple has been really helping gaining and increasing my trust for Linux. I think I'll start making preps for the tranfer.

I have seemed to have stumbled upon a solution that so far is working for me. I'm not saying this will work for all, yet might be worth a try.

After doing a SMC reset (https://support.apple.com/en-us/HT201295), I started to get different crash reports mainly about memory. This seemed to be when I was encoding and the screen shut off, or having nothing on the screen at all and after 10 min the computer would reboot. So I downloaded 'Rember' (https://www.kelleycomputing.net/rember/). This showed an error within the memory even though the Apple Hardware Test (https://support.apple.com/en-us/HT201257) showed everything was ok.

I have a 2019 iMac i9 With the Vega 48 GPU. I added 2 x 16GB OWC compatible memory chips to the already installed 2 x 4GB that came with the iMac for a total of 40gb. Apple memory in slots 1,3 and OWC in 2,4 as recommended.

I took out the OWC memory, and the computer booted faster and the memory test came back good. So I decided to take the apple memory out and test just the OWC memory, in slots 1,3. Again the computer booted faster and the memory test came back good. I started to do benchmark tests, Geekbench all of a sudden shows my i9 chip was faster, weird. Novabench CPU score jumped almost a 100 points.

So far with the screen setting back to shutting off after 10mins, during encoding and while doing nothing my iMac seem stable with just the 32GB of OWC memory.

Anyways... again this is not a solution to everyone's issues.

Until there is a fix, this is the workaround that is stable and working for me.

In Energy Saver System preferences, for both battery and power adapter:

• Set "Turn display off after" to NEVER.
• Tick "Prevent computer from sleeping automatically when the screen is off"

In Desktop & Screensaver

• Change "Start after" to NEVER.

When I finish work, I manually sleep the mac using the Apple menu and Sleep. Obviously this means your computer is using more power and the battery will drain faster, but you shouldn't have crashes.

Hot corners for "Put display to sleep" are actually working ok for me as is manually sleeping.

If anyone else is having trouble with this Catalina sleep/crash/restart/kernel panic problem, please let me know if this helps you too so that others can know of a workaround.

I am having the same issue. When I return the screen is a blue/pink swirl of color, or the computer has shut down and I need two restart. Sometimes the system completely freezes, and sometimes I am able to get it running again without a restart. If it goes into sleep mode, even if I do this manually, it crashes upon waking up ever since the upgrade.

I thought that this would help - and it did for few days - but last night I had this same crash again.

I have an open AppleCare ticket and sent log files to them this morning.

Case still open, no permanent solution found, except unplugging external monitors :(

This will some what repeat what I said last time but this is purely on the steps that I took as advised by Apple support. This is the last step for a solution according to my rep. I went over 24 hours with this solution and I have not experienced 1 single crash. In fact, the upside to this, my computer is some how running the most smooth it ever has in comparison to the other 2018 and 2017 MacBook Pros I have owned. I think this will be the steps I take for each major update. The solution is purely a clean install of the OS so make sure you run the Time Machine backup first before you proceed.

1) Run Time Machine Backup

2) Restart the computer and hold Cmd+R before the Apple logo appears

3) Log into Disk Utility and erase the hard drive. If you have both Macintosh HD and Macintosh-Data, erase both drives and delete one of the patricians. (Caution: You may have to perform this action a couple of times or even create a new blank Partitian and delete the others - I had to do this very thing to have a function blank drive - yeah, it did get complicated but it was worth it)

4) Exit the disk utility and run a clean install of the Catalina operating system. DO NOT run that install with Time Machine or run the Time Machine restore... This is to be purely a clean install as if you just bought the computer.

5) When you run the install and initiate a user profile create, do not create the same user profile that is on your back, name it something else.

6) Log in to your new clean install, test the monitors with the computer, recreate the environment that would cause the crash. If you are crash free, then close all programs and windows, you are ready for the next step.

7) Click on the search icon for "Spotlight Search" in the upper right corner, search for "Migration Assistant", then run the Migration Assistant from your most recent backup. This will allow the transfer of the files over without the installation of the buggy OS.

8) With the back files successfully transferred back over, you can now log into your original user profile with programs and files.

9) Don't celebrate yet, you need to check your computer for any invalid programs and or files. When I cleared these out, I found my system also performing much better. May I recommend "App Cleaner & Uninstall" to assist you.

Once again, I'm on 24 hours now without debugging, without fixing and without a crash. If I experience a crash again I will post but so far I have a way better performing computer now than I have had before. But this solution is still no excuse for Apple to not address this very issue. So far I have had terrific reps who has been with me every step of the way and I have a direct line to my rep just in case if this issue reoccurs.

This is a complex fix and requires surgical precision when performing it. Good luck and let me know how it goes for you.

Mine crashed and would not recover until I tried all kinds of resets. Sometimes it would only fan-on for a few seconds and then crash straight away again. Of course I eventually unplugged the external screen and had better luck. it still crashes now so I stopped the computer from sleeping in any way. It scared me but I'm glad others have similar issues and it's maybe not a hardware fault. I was so close to taking it into a repair shop. Not cool Apple... I've wasted over 24 hours dealing with Catalina issues. From now on I'm NEVER installing a new OS until it's at least 6 months old.

Hi mrbofus, it's interesting you say to use a different user name... I wonder if it's related to my other issue I'm having with user accounts. I noticed a bug where I deleted and created a new admin account but with the same name.... anyway the computer is always confused as to which password to accept for admin access. Sometimes it allows the new password - sometimes not! - this is really really strange behaviour.

I've been seeing degradation on my MacBook as well since the upgrade last week. Two hard crashes. Both times, attached external monitors (once at my home office, once at work office, so different monitor configurations). Noticed that in general the machine has had a hard time recognizing the monitors and placing them correctly since the update, so wouldn't at all be surprised if this is some sort of graphics driver issue. Have not had a crash without external monitors but will try that later tonight. Yeah, Apple needs to resolve ASAP, this is not a "minor" bug.

MacBook Pro (15-inch, 2017)

2.9 Ghz Quad-Core Intel Core i7

16 GB 2133 Mhz LPDDR3

Radeon Pro 560 4 GB

Intel HD Graphics 630 1536 MB

j5create docks at home

Belkin dock at work

One note worth adding: I've also had issues with my Dock disappearing only to come back after reboot, then eventually never coming back until I've deleted the docking plist file under library\preferences. When it occurs "Automatically hide and show the Dock" is checked in the Dock preferences even though I've never checked it and unchecking doesn't do anything. Related? Who knows.

My work-around for a late 2017 MacBook Pro running an external monitor, is to top change all settings related to screen savers and energy savings is to never turn off or nap. I just shut the lid when away. I have had no crashes in 36 hours using this method.

I can reproduce while the machine isn't connected to docking stations or external monitors.

Also, if it happens while I'm away (i.e. the computer is locked and goes to sleep) I come back to find the graphical function bar flashing, screen black, but it looks like the backight is turning on and off. Have to force a hard shut down then restart to get the machine back up.