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

I have the same issue, kernel panic when plugged into external monitor. It has happened to me twice in the last three days I've had the computer (16' MBP with i9 9880H and Radeon Pro 5500M 4GB). But I have a different error message:

Thanks for looking into my issue! I have had the same error message twice in the past week (deadbeee instead of deadbeef). The first time I had the issue, I did not have any hypervisors installed on my system. Both cases happended exactly when I plug in my Dell U3415W monitor with a USB-C to DisplayPort connector. I think the chances of hardware failure causing the same bit flip at the same offset is very small. I have also run the Apple Hardware Test and Memtest86, both passed with no errors. I think it is very likely a driver related bug.

"The only thing that helps is disabling sleep mode. "

Actually, as of 10.15.3 , it doesn't. The update actually made it worse.

Just got two kernel panics in one hour. What a joke. The thing is more stable running windows than Mac OS

If anybody is starting class action, i'm certainly in.

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?)

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.

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.

The engineers who talk directly to customers do not get told the exact issue, and because Apple is so secretive, they have no way of discovering the exact issue.

If they say it is Hardware, then send them your Mac and have them fix it, guaranteed.

It is absolutely beyond me why you haven't been expelled from this forum already.

The sheer amount of ignorance and complete lack of knowledge is simply unbelievable.

There is absolutely no evidence supporting your "Problem with graphics chip" theory. This is pure uneducated speculation.

You spread these theories while completely ignoring the technical facts (such as the problem neither appearing in bootcamp or w/o any monitors in MacOS) as well as user reports clearly stating that the problem persists after a motherboard replacement.

BTW, the so called engineers are not development engineers. They are specially trained support people who have as little of a clue as our dear Grant.

NNEU wrote:

...

It is absolutely beyond me why you haven't been expelled from this forum already.

Because other Users have awarded me in excess of 89,100 points for responses they deemed at least "helpful". I have achieved level 10, the highest level of helpfulness for senior technical contributors on these forums..

If you do not find my advice helpful, I suggest you ignore it. If you like, I will personally refund the full amount you paid for that advice.

Trying to contact them; have requested a replacement and Apple stating that is not an option.

All information being posted to try to help understand what the problem is and being experienced by others as well, and following up with described problem that a logic board replacement did not solve the issue.

That's really odd. Not sure what Powernap is doing that requires disabling it to avoid KP's. I have PowerNap enabled on my 16" MBP and I've never experienced a KP. I've had it since late January. In fact it's been perfect all the way around.

I think the issues are occurring when connected to external monitors I suspect, in particular the Apple-endorsed LG 5K monitors, though it happens if connected to two Dell UHD monitors as well. Happens when manually placing the computer to sleep, or if the computer goes to sleep on its own. Using LG thunderbolt usb-c cables supplied with monitor directly, or in the case with Dell, one with an HDMI cable connected to the Apple adaptor. Have tried Apple thunderbolt cables direct to monitor and computer for LG as well.

Very frustrating. This issue has been going on for some time and not getting resolved.

"Very frustrating. This issue has been going on for some time and not getting resolved."

Perhaps because it's not affecting as many people as you may think. Case in point, I've never experienced a kernel panic and I'm a power user editing Final Cut Pro X and Logic Pro X projects weekly. It may be just a bad run of shipped computers. That does happen at times, but forums should never be used as law that something is widespread and not getting resolved simply because it's amongst forum members that are experiencing issues.

"The issue described for this situation has been going on for some time now without resolution in this case, and others as described, no one has suggested the forum be used as law or stated it is a widespread event that I'm aware of. "

I was only making a point, but just the fact that you are dismissing that my MacBook Pro is working fine and you're only focusing on the people with the problem you are suggesting that it's "widespread". I do hope get your issue resolved but please don't dismiss people without issues. It's important to the forum that both good experiences and adverse ones are posted and accepted. Best of luck.

Your repair comes with a modest warranty. If the problem is not resolved, send it back to the repair vendor and ask them to "Make it right".

Be sure to be Very Explicit about how to reproduce the errors you are still seeing, or they will not know how to make it crash, and will not know when it is fixed..