Kernel Panic on Shut Down and Boot

I have the exact same problem. It happens (almost) every time I shut down. New MacBook Pro 16, problem just started when I upgraded to Big Sur. There are no diagnostic reports I can find except the ones like the one belleslettres posted above. I doubt this is hardware -- if you search even a bit there are MANY posts with exactly the same issue.

The one thing I have noticed that is POSSIBLY related is the following: (a) I have an Apple TimeMachine doing my backups (actually two on my network) and when I make sure the TimeMachine is not running it sometimes causes the failure not to happen; and (b) I have seen posts where people believe similar crashes are related to Big Sur's preference for case sensitive APFS disk support (search Google for "big sur apfs kernel panic shutdown"). They recommend reformatting your TMs and starting your backups over. I have not yet gone to this step since my backups are FileVault and I don't yet want to spend a full day rebuilding my backups just in case I can work around a bug Apple does not care to diagnose and fix.

More tools to help us figure out what component is crashing would be helpful. I feel like we are flying blind here.

if you search even a bit there are MANY posts with exactly the same issue.

Why could that not be a hardware problem.

There have been at least two wide-spread hardware problems with brand new Macs, the 15" Mid-2010 MacBook Pros shipped with bad GPUs and there was also an iMac model with a similar GPU problem.

The Mid-2010 MBP often did not show signs of problems until upgrading to Lion, but still some saw the problem in Snow Leopard. So, a hardware problem can exist without signs of it in one OS, but show up in another.

If you believe a brand new Mac cannot have a hardware problem, you are quite mistaken.

Point well taken, thank you. It certainly could be hardware and that is definitely something worth checking out as you suggest because there is plenty of history. My doubts of the hardware came from posts of (what appear to me as) similar events that seem to happen on varied hardware configurations (mine on an intel chip, others on the Apple silicon -- but this does not necessarily imply that there are not other common hardware components, like for example a network attached TimeMachine or some other peripheral). Since the big change for me was Big Sur, and since I saw other examples of different systems that all happened after a Big Sur upgrade, I went to software as my prime suspect.

The one frustration I really was most focused on was the lack of diagnostic tools available to narrow this down. It would be great if the report posted above (and similar to my own) would actually identify the module associated with the problem. Was it a backup task, system virtual storage management, an antivirus program that crashed? This would be be SO helpful, but it's just not available from what I can understand from the data shown. I tried to find more information in the logs directory, but there was simply nothing there and so there was nothing there to go on either.

I think that is what this really boils down to for me. This is a complex product, no doubt. And add to that the fact that every user puts their own extension products on top of it does not make it any easier. To narrow it down it does often require a lot of ground work (like testing all of the hardware, like sometimes reloading the operating system, ...). But in the end, if the panic report just gave us a few clues on what software component was running when the panic occurred it would probably save a lot of time boiling the ocean.

The one frustration I really was most focused on was the lack of diagnostic tools available to narrow this down. It would be great if the report posted above (and similar to my own) would actually identify the module associated with the problem.

None of that information is available in a kernel panic. A kernel panic is an unexpected fatal error that was not handled at all. If it could be handled or the source known, it wouldn't have panicked.

It can sometimes provide what is currently running at the time, but that almost never is directly related to what caused the panic because it is just what was coincidentally going on at the time. The kernel code is running so far below the level of frameworks and applications that it almost never can show what was the cause.

Normally, the kernel panic does have a backtrace, again not conclusive but coincidental. Your panic looks like a logic board problem, not a kernel extension bug. But, I have seen panics caused by AV kernel extensions that look more like hardware faults than common kernel extension bugs.

If you have any third-party kernel extensions installed, uninstall them.

The diagnostic tools are available at an Apple Store or Authorized Repair Center.

That's probably a hardware problem. Take it to an Apple Store or Authorized Repair center if the panics continue.

What you've posted is useless.

The entire report is needed.

As @Barney-15E suggested.

Though, an chance there is AntiVirus software installed. This insidious software really does interfere with the OS in profound ways.