MacBook Pro 16" Kernal Panic During Restart when Plugged into Dual Monitors

I have same issue here,

2 monitors attached, but the issue also happens with only one but with less frequency...

as it happens on wake up, with lid closed or not and it seems to be random

i have done a kernel debug and found out that the issue happens only when the system wakes us making a call to core 0

i guess it is a software bug and i really hope Apple will look into this asap as it is extremely annoying...

if you guys have any suggestion or work around all is welcome

cheers

I got the exact same issue, maxed out 16” MBP and this only happens to me when I connect my laptop to 2 x LG 5k Ultrafines, I initially thought this was a problem with my machine specifically but apple gave me brand new one and I had the same issue. I do have a 2018 15” MBP also maxed out from work and that one doesn’t have this problem. I’m really not sure what’s going on but when you spend this much on a machine this is absolutely ridiculous. Apple needs to fix this.

Same problem. Macbook Pro 16" 2.3 GHz 8-Core with 64 GB memory, AMD 5500 8 Gb. When connected to external monitors with the lid closed, get kernel panics during wake up from sleep, sometimes during shutdown, sometimes randomly. I do not recall panics apart from the external monitors (three NEC monitors). In addition to crash messages similar to what others above have posted, I've also gotten the 'Bad Magic!' error message reported in other forum posts.

I've been a Mac user and evangelist for a long time. This is simply getting intolerable between hardware issues like keyboard failures with the last batch of Macbook Pros and the worsening stability of the underlying OS. (How do you take a Unix foundation and mess it up so that it crashes so much?)

+1 here. Fully specced MBP 16 attached to one LG Ultrafine 5k and on sleep, the laptop has a kernel panic and shuts down. Super annoying. Tried uninstalling Dropbox and other apps that were appearing in the log, but did not do any good. Also tried reinstalling MacOS (no reformat though) and this didn't change anything. The only reason I was able to figure out the kernel panics are related to the monitor is because when the laptop is unplugged, this problem does not present itself. Based on everyone's experience here, it does seem to point to some bug in MacOS that needs to be addressed ASAP. I cannot have my machine crashing on sleep, especially when I have my work in progress open on the machine. Apple please fix!

My configuration is the same although it is not necessarily related to sleep. It will work fine for days and then lock-up every hour for 6 hours and then work fine for 2 days. Never occurs without the LG Ultrafine detached. Now, I disconnect the monitor when doing anything "important" to prevent data loss. (or use my 2014 13" which is rock solid). Super frustrating but there aren't motherboards from what I have read so am waiting it out and retaining all crash logs.

There should be an adequate supply of service parts available at an Apple depot if you arrange to have it sent in for a repair.

What part of the world are you in? who told you parts are not available?

This is not a hardware issue. Grant, the exact problem is that there is no simple Hardware fix.

There are plenty people who had their entire motherboards replaced and still had the problem.

Plus a ton of work to backup data and restore the machine.

I know this from first hand experience.

Also, this issue does not occur in bootcamp, which it would have to if it were (purely) hardware related.

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I've been in contact with service and now they are wanting my machine in, stating it is a hardware issue and in need of repair, but will not tell me exactly what the problem or intended repair will be. The problem ONLY occurs when connected to the two LG UltraFine monitors. Took it to the local Apple store for examination and they stated it was a software problem. The computer works fine and does not crash upon sleep when it is not connected to the monitors. Very, very frustrating.

Hey I had this problem, they did the same to me and gave me a new computer but the issue wasn’t resolved. However with The latest OS update it half fixed it for me. So now I don’t get that problem when restarting or shutting the computer down but I do get a crash “sometimes” when my computer goes to sleep. It’s definitely a software issue. Make sure you update to macOS Catalina 10.15.4 and see if that works for you.

Yes, I am only experiencing this when the computer— connected to one or both LG monitors — goes to sleep. It crashes upon awakening. LG display software up todate. Apple support when taking to a store for examination said it was software. Now Apple support says it is a hardware issue and needs to be sent in based on the same error messages, but refuses to tell me what exactly will be repaired. The computer goes to sleep and fine when not connected to the displays. Very frustrating. I fear I’m sending it in and will have the same problems when I get it back.

gmiles wrote:

...

refuses to tell me what exactly will be repaired.

Over the last five years, Apple has been moving to fewer assemblies of greater complexity.

The only appropriate thing to be repaired (by replacement) is the mainboard, which now contains the processor, System Management Controller/T2 chip, graphics chips, graphics RAM, main RAM and Boot drive.

When all that has been replaced, your computer will be just like a brand new one..

What is frustrating is that when the computer was taken into an Apple Store and checked over, I was told there was no hardware issue. Now, after submitting and having the same error messages reviewed by Apple Support over the phone, am being told it is a hardware issue and needs repair.

What hardware issues would only occur when the computer is left to go to sleep when connected to the 2 LG ultra fine displays, and then crash upon awakening? If it were a hardware issue, why then would the computer work with the 2 LG displays when the computer is awake and being used? This seems all very very strange.

gmiles wrote:

...

Now, after submitting and having the same error messages reviewed by Apple Support over the phone, am being told it is a hardware issue and needs repair.

Some Time has gone by, and Apple as a company has had more examples of this failure, and more ability to re-create the problem and understand why it is happening.

This is likely a very unusual failure of the new Graphics chips used for the first time in theses MacBooks. Later versions of the same chip may have this problem fixed.

I still find this difficult to understand as the difference in timing between in-store and on-phone support on the same issue is really only a few weeks, really not that much time. Apple sells the LG monitors in their stores and on-line, so I question why this problem wasn't re-created in the back with tech (it may or may not have been, not clear what was done other than a thorough hardware check per staff, saying everything ok, must be a software problem, sorry not much else can be done). And why over the phone, after multiple phone calls trying to escalate the issue to the proper channels, now getting a completely different story, looking at the same data and problems. I've been a loyal Mac customer for decades now, but have to say that something has changed in the support area.

Hi, we tried this approach with Apple Support after several troubleshooting sessions, but was still getting the kernel panics after changing these settings. Same error messages were then routed to Apple Engineers, a week later was notified by Apple Support that it was a hardware issue, but would not disclose what issue or any specifics when directly asked several times. If it were a hardware issue I would think that one would be seeing more problems when actively using, not just when the computer goes to sleep at night/woke up the next morning to see it crashed.