MacBook Pro M5 Max Kernel Panic with Thunderbolt 5 dock and P2715Q Displays.

Same crash here, on a third brand of dock.

16-inch MacBook Pro M5 Max (Mac17,6), macOS 27.0.1 (26A434), Anker Prime Thunderbolt 5 dock (A83B5, Thunderbolt NVM 64.1). Plugging my Dell P2715Q into the dock (USB-C to DisplayPort cable, into one of the dock's downstream Thunderbolt ports) panics the Mac within seconds:

ACIO0 Recoverable Panic - assert_id=9450 - ACIO main workloop(2)

ACIO firmware 761.0.3. That's six panics so far, on two ports (ACIO0 and ACIO1), and one was on a certified 240 W Thunderbolt 5 cable, so it isn't the cable.

Same controls as yours: the dock, cable and P2715Q all work on my M1 Max, and the P2715Q works plugged straight into the M5 Max. My Dell U2720QM runs through the same dock without trouble.

CalDigit owners report the same assert on the TS5 Plus. One has a P2715Q on an M5 MacBook Pro under macOS 26.5, back in May:

https://www.reddit.com/r/CalDigit/comments/1tps8jg/caldigit_ts5_plus_with_dp_causes_kernel_panic/

Another has an M4 Pro with LG 5K monitors and kept getting it after CalDigit's 71.1 firmware update:

https://www.reddit.com/r/CalDigit/comments/1wrjj99/m4_pro_caldigit_ts5_plus_monitors_wont_wake/

With iVanky, Anker and CalDigit docks all hitting the same assert, it looks like Apple's Thunderbolt controller firmware rather than any one dock.

I've filed Feedback***. If you've filed one, could you post its number? Anyone else seeing this, please file your own report and mention these numbers so Apple can link them.

For now my P2715Q is plugged straight into the Mac. Next I'll try the dock's HDMI port, since a CalDigit owner's P2415Q worked over HDMI at 30 Hz, and I'll report back here.

[Edited by Moderator]

<< I tried plugging in a Dell U2412MB display via a DisplayPort cable to the fusiondock ultra, no kernel panic. 

I tried plugging in a Samsung U28E590 display via DisplayPort to DisplayPort cable, no kernel panic. >>

There sure are a lot of moving parts in this one.

It seems like All panic cases come from the 2715 display OR the USB-C to DisplayPort adapter, or Both, when used on the FusionDock. ¿is that correct?

next try isolating the USB-C adapter:

plug one of those two well behaved display using the same USB-C to DisplayPort adapter you have been using, off the Dock, to see if this issue mainly follows the adapter-on-Dock.

Update

I have gotten the computer back from the Apple Store.  They could find no hardware faults, and reinstalled Golden Gate 27.0.1.

I got back to my office and plugged the FusionDock Ultra in with all the peripherals attached, which was running fine on my M1 Max.  The computer didn't even get to the account setup portion of the setup process.  It kernel panicked and restarted.  I let it loop through this about 4 times before I gave up and unplugged the dock.  

I’ve plugged two monitors (P2715Q) back into the Microsoft Surface Thunderbolt Dock, and the third display into the MacBook Pro itself.  No kernel panics yet.  

Kernel panic is Not ONE problem, its is one of Thousands of problems.

Kernel Panic Reports are stored in the Folder at:

/Library/Logs/DiagnosticReports

If you copy and paste that string into:

Finder > Go menu > Go to Folder

it will take you to the Folder where those reports are stored.

Kernel panic reports are named with Date&Time and start or end in ‘panic’

If you find one, please post as much as you can here, by using the “additional text” Icon in the reply footer (looks like a paper with writing). (Once the report devolves into incessant software-names or incessant Base-64 dumps with lots of AAAAAA lines, you are done.)

Please don’t post more about 20 lines of any other types of reports — they are interminable, and any information useful for this purpose is on the first screenful.

If you post your kernel panic here in its entirety, using the additional text icon in the reply footer, we do have some Readers (typically with developer background) who can attempt to interpret those panic reports. Even if no clear symptom emerges, this can still save a step if you DO need to contact Apple support later, because Apple Support specialists can read the panic reports you posted here, if you tell them what discussion or what Avatar.

something is wrong somewhere.

On the graphics & displays page those 3 direct-connected 2715 4K displays are ALL reporting as 5K 5120 by 2880 displays.

When connected to the dock with adapter, the Samsung 4K display is reporting as a 5K display.

to collect more supporting information, try using:

Option-Apple menu > system Information > Graphics and Displays

you get something like this and its all text so can be cut and pasted:

then take a look at Thunderbolt ports and USB ports in a similar way, and see if that shows any unexpected information about that adapter or the Dock outputs with a good display connected through the Dock and the adapter.

I don't have a good example on hand, this is the best I have stored:

I must admit that the "looks like" resolution has gone through a whole lot of changes over time. Not reporting the actual resolution is not very helpful when debugging.

can you post the ThunderBolt report with the Samsung display plugged in with adapter, and show the actual display's connection?

Dell P2715Q appears to be a 4K display with refresh rates to 76 Hz.

interfaces include:

• HDMI 1.4 -- severely limited to 4K at 30 Hz when limited to 8 bits/color

• DisplayPort 1.2 and Mini DisplayPort 1.2 -- which can support HBR2 at 17.25 G bits/sec (still sub USB-3 Display data rates) good for 4K at 60 Hz before Display Stream Compression

¿what version MacOS are you running here?

<< This also happens in the recovery environment. >>

that virtually eliminates added software as the culprit

how are you connecting the dock to the Mac? using their dual-cable or a single cable?

The Dell 2412MB is an HD display -- not nearly as "interesting" that it did not cause a panic.

the Samsung U28E590 appears to be a 4K display.

why did you connect those with a DisplayPort-DisplayPort cable?

how did you connect the two Dell P2715Q, they have no USB-C display data inputs? what adapters are you using?

I have just dropped the machine off with the local Apple Store for them to diagnose. I have exhausted my resources in the office, and haven't gotten anywhere. I will update this thread when I hear back from them. Because I had kernel panics from day one with this machine I had updated to MacOS 27 via the public beta channel then turned off the beta versions once the GM was released. Apparently the recovery partition was still beta, which the Apple Store employees told me they were not allowed to diagnose or touch.

So FYI to anyone trying to restore your machine after wiping all partitions you can through disk utility in the recovery environment. You will not be restoring from the internet but from a hidden partition with an unknown version of MacOS.

When I asked what hardware tests they were going to run I was told testing was a trade secret and essentially none of my business, which was not what I was expecting.

On another note, plugging my M1 Max MacBook Pro into the FusionDock Ultra with all my peripherals working is a breath of fresh air.

New Update:

Computer is back to freezing and restarting while waking from sleep when plugged into the Surface Thunderbolt 4 Dock. The Fusiondock Ultra replacement came and the behavior has not changed. Kernel panic the moment I plug my Dell P2715Q in.

In testing with apple support over the phone, the computer will freeze and boot loop even while in the recovery environment if I plug any of these dell monitors (P2715Q) into the FusionDock Ultra. I'm beginning to feel that there some something wrong with the hardware.

I am running macOS Golden Gate 27.2, which installed itself after all partitions were wiped.

The displays are all 4k (3840x2160) capable running at 60hz.

Concerning the kernel panic logs, they appear to be in /Library/Logs/DiagnosticReports/Retired and are named panic-full-"date"-"somestring".panic. The date appear to correspond with kernel panics, would you like me to post their contents?

<< would you like me to post their contents? >>

yes, please start with one. You can use the 'additional text' icon in the reply footer to get a bigger window to put a full panic report into.

Panic Log below. This kernel panic happened immediately after entering my password to log in, as I left the FusionDock Ultra and Dell P2715Q plugged in after a previous kernel panic.

I stopped at the SOCDNandContainer portion of the kernel panic log. The only other portion below that is the memorystatus messages which I also did not post.

That's a non-interesting RECOVERABLE panic -- should not have stopped your Mac,

 "panicString" : "panic(cpu 16 caller 0xfffffe0039769a74): ACIO1 Recoverable Panic -  assert_id=9450 - ACIO main workloop(2

The FusionDock Ultra is connected with the two cables that it came with. I've tried flipping them over. Always using the dual cable per the instructions.

The other two monitors were connected with DisplayPort to DisplayPort cables because that was the most advanced port on them. The had DVI (the other dell) and HDMI (Samsung).

The Dell P2715Q monitors can be hooked up via DisplayPort or mini DisplayPort. I have tried both, each results in a kernel panic. I have also tried a DisplayPort to USB C cable, making Sure the cable supports DP alt mode. Also results in a kernel panic. Every kernel panic is immediate. I have tried all cables but HDMI as I want more than 30 hz.

To make sure it wasn't a data issue I manually turned the Samsung display up to 2160p at 60 hz. No kernel panic.

<<next try isolating the USB-C adapter:>>

Good idea,

I just used one of the DisplayPort to USB C cables from a P2715Q and plugged the Samsung U28E590 into the FusionDock Ultra. No kernel panic, monitor functioned as expected.

I think adapters can be ruled out. The P2715Q displays work fine when plugged directly into the M5 Max MacBook Pro but kernel panic with the FusionDock Ultra. No kernel panics when using my M1 Max MacBook Pro in the same configuration.

Attached are some screen captures.

This is with the three P2715Q displays connected directly to the MacBook Pro.

Below is with the Samsung U28E590 plugged into the FusionDock Ultra via a DisplayPort to USB C.

Below is with the FusionDock Ultra plugged into the MacBook Pro with the Samsung U28E590 plugged into the dock.

Below is the USB tree with the FusionDock Ultra plugged into the MacBook Pro.

Nothing jumps out as wrong, the only thing I noticed is that Thunderbolt Bus 2 does not have any MicroFirmware information. See below.

Every kernel panic that I send to Apple via feedback assistant starts with that string. But the machine locks up for about 10 seconds, no input works. Then it restarts.

I believe this is due to macOS internal resolution scaling. It upscales what it’s rendering then outputs to the desired “looks like” resolution. But I’m not positive.