Big Sur panic when connect/disconnect usb-c dock

Big Sur panic when connect/disconnect usb-c dock (tested with many usb–c docks including baseus, ugreen, non apple – not reproduced with apple multiport adapter).

Problem persist! I have many panics every day!

panic(cpu 7 caller 0xffffff8017898976): [kext.kalloc.2048]: element modified after free (off:1672, val:0xffffffff00000000, sz:2048, ptr:0xffffff93d7fa5800, prot:zero)
1672: 0xffffffff00000000
Backtrace (CPU 7), Frame : Return Address
0xffffffa1daab2640 : 0xffffff80170870ad
0xffffffa1daab2690 : 0xffffff80171cddd3
0xffffffa1daab26d0 : 0xffffff80171be3ca
0xffffffa1daab2720 : 0xffffff801702ba2f
0xffffffa1daab2740 : 0xffffff80170868cd
0xffffffa1daab2860 : 0xffffff8017086bc3
0xffffffa1daab28d0 : 0xffffff801789694a
0xffffffa1daab2940 : 0xffffff8017898976
0xffffffa1daab2dc0 : 0xffffff80170e5a26
0xffffffa1daab2e30 : 0xffffff801709668c
0xffffffa1daab2e80 : 0xffffff80177a8822
0xffffffa1daab2ea0 : 0xffffff801a1596dc
0xffffffa1daab2ec0 : 0xffffff801a1676bc
0xffffffa1daab2f20 : 0xffffff801a159e2e
0xffffffa1daab2fc0 : 0xffffff801a15bfa7
0xffffffa1daab3270 : 0xffffff801a15fe3d
0xffffffa1daab3540 : 0xffffff801a15cda2
0xffffffa1daab37f0 : 0xffffff801a15a333
0xffffffa1daab3950 : 0xffffff801a1547b1
0xffffffa1daab3b50 : 0xffffff801787fb4a
0xffffffa1daab3b90 : 0xffffff801731a98f
0xffffffa1daab3bd0 : 0xffffff80173407c8
0xffffffa1daab3c90 : 0xffffff80173264a8
0xffffffa1daab3ee0 : 0xffffff8017327059
0xffffffa1daab3f40 : 0xffffff8017739fce
0xffffffa1daab3fa0 : 0xffffff801702c1f6
Kernel Extensions in backtrace:
com.apple.security.sandbox(300.0)[F9746111-2761-31A8-A9C8-3DCA8976E468]@0xffffff801a148000->0xffffff801a18dfff
dependency: com.apple.driver.AppleMobileFileIntegrity(1.0.5)[7C10DA84-DFD9-3C2D-B503-E648E488EC9D]@0xffffff80186c0000->0xffffff80186d5fff
dependency: com.apple.iokit.IOStorageFamily(2.1)[A78CAAA2-43A6-38EF-AEDA-3B957D358855]@0xffffff8019c6d000->0xffffff8019c7efff
dependency: com.apple.kext.AppleMatch(1.0.0d1)[DB7AEFA5-928C-3B7F-87CC-EDC47D98B267]@0xffffff80186bc000->0xffffff80186befff

Process name corresponding to current thread: update_dyld_sim_shared_cache
Boot args: chunklist-security-epoch=0 -chunklist-no-rev2-dev

Mac OS version:
20F5046g

Kernel version:
Darwin Kernel Version 20.5.0: Thu Apr 15 05:31:19 PDT 2021; root:xnu-7195.120.38.111.1~4/RELEASE_X86_64

My reports in feedback assistant: FB9085399, FB9084201, FB9080122, FB9078447, FB9077541, FB9073646, FB9069424, FB9036423, FB9006281, FB8996761, FB8985931, FB8984349, FB8982979 ...

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Posted by
trukhinyuri
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  • I have a 16" 2019 MBP running Big Sur 11.4 and I'm use an HP Thunderbolt Dock G2 with my monitors connected via USB-C.

    I get this all the time. Sometimes it can be all of a sudden in the middle of a session, but it is much more prevalent when I am plugging in/out of the dock. It also occurs when the laptop wakes up after being in sleep mode. I get the quick sound of the fans blowing and then it reboots. It happens way too many times. I have no other option in terms of trying other docks.

    I report the error every time I get it. It has been going on since the Big Sur upgrade.

    —
    dbdotconf

  • Are you connecting your monitor via DisplayPort? Try using HDMI instead - my laptop only crashes with DisplayPort, never with HDMI. Also, try connecting your monitor without the dock (get a USB-C to HDMI cable) to rule out a problem with dock

    —
    scarvalhojr

  • Happens to me as well as described by @dbdotconf. I use 2 monitors with 16'' 2021 Big Sur 11.5.1. The same flow of actions, almost every day when I plug in monitors via 2 TB3, I hear fans and then it crashes and reboots. Also send report every time. This is very annoying. Such amount of money was paid not for such an experience with Mac which is supposed to be ideal.

    —
    ruuuuk

Replies

still nothing fixed with 11.5 beta 2, whether Apple simply has no more priority on it or they can just add new bugs and not fix any more because missing knowledge on this topic.

Posted by
mnin
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I have the same problem on my MacBook Pro (16-inch, 2019), with the CalDigit USB-C Pro Dock (which is confusingly actually Thunderbolt 3). I have a 4K screen attached to the Dock over HDMI. I get the kernel panic with "modified after free" when I plug in the dock.

I'm pretty sure the kernel panics started with the Big Sur 11.3.1 update for me. The 11.4 update didn't fix it.

My wife is using the same dock with her M1 MacBook Air and does not see the issue.

Posted by
sbesselsen31
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I have had this happening for months now. This is becoming a daily pain to deal with at office now given how often I have to undock my MBP and move around. I finally got frustrated enough to reset my NVRAM/erase disk/reinstall Big Sur and it happened again immediately before I even starting reinstalling software.

It was bad enough having to unplug/replug the dock to just get my second monitor active again in the past. The kernel panics have made this so much worse.

I am using a CalDigit USB-C Pro Dock at work and a CalDigit TS3 Plus Thunderbolt 3 Dock at home, both cause the issue.

 1672: 0xfffffffe00000000
Backtrace (CPU 3), Frame : Return Address
0xffffffb0e409ac10 : 0xffffff801c48e0dd 
0xffffffb0e409ac60 : 0xffffff801c5d4f33 
0xffffffb0e409aca0 : 0xffffff801c5c552a 
0xffffffb0e409acf0 : 0xffffff801c432a2f 
0xffffffb0e409ad10 : 0xffffff801c48d8fd 
0xffffffb0e409ae30 : 0xffffff801c48dbf3 
0xffffffb0e409aea0 : 0xffffff801cc9d81a 
0xffffffb0e409af10 : 0xffffff801cc9f846 
0xffffffb0e409b390 : 0xffffff801c4ecad6 
0xffffffb0e409b400 : 0xffffff801c49d6bc 
0xffffffb0e409b450 : 0xffffff801cbae4f2 
0xffffffb0e409b470 : 0xffffff801f55a41c 
0xffffffb0e409b490 : 0xffffff801f5683fc 
0xffffffb0e409b4f0 : 0xffffff801f55ab6e 
0xffffffb0e409b590 : 0xffffff801f55cce7 
0xffffffb0e409b840 : 0xffffff801f55b073 
0xffffffb0e409b9a0 : 0xffffff801f56b882 
0xffffffb0e409bbb0 : 0xffffff801f56b564 
0xffffffb0e409bed0 : 0xffffff801cc79f5e 
0xffffffb0e409bf40 : 0xffffff801cb3fc9e 
0xffffffb0e409bfa0 : 0xffffff801c4331f6 
      Kernel Extensions in backtrace:
         com.apple.security.sandbox(300.0)[C7CC6439-6854-33FB-9E97-F468B75AD280]@0xffffff801f549000->0xffffff801f58efff
            dependency: com.apple.driver.AppleMobileFileIntegrity(1.0.5)[366C7BD4-9502-3D1C-ABBE-DE9749913D0C]@0xffffff801dac0000->0xffffff801dad5fff
            dependency: com.apple.iokit.IOStorageFamily(2.1)[A0D72FE9-649B-316A-8B5C-934E295FF0B5]@0xffffff801f06d000->0xffffff801f07efff
            dependency: com.apple.kext.AppleMatch(1.0.0d1)[759DEBDE-C844-3703-A01C-4DF5EEA8F4ED]@0xffffff801dabc000->0xffffff801dabefff

Process name corresponding to current thread: mds
Boot args: chunklist-security-epoch=0 -chunklist-no-rev2-dev

Mac OS version:
20F71

Kernel version:
Darwin Kernel Version 20.5.0: Sat May  8 05:10:33 PDT 2021; root:xnu-7195.121.3~9/RELEASE_X86_64
Kernel UUID: 52A1E876-863E-38E3-AC80-09BBAB13B752
KernelCache slide: 0x000000001c200000
KernelCache base:  0xffffff801c400000
Kernel slide:      0x000000001c210000
Kernel text base:  0xffffff801c410000
__HIB  text base: 0xffffff801c300000
System model name: MacBookPro16,1 (Mac-E1008331FDC96864)
System shutdown begun: NO
Hibernation exit count: 0

System uptime in nanoseconds: 5557308287228
Last Sleep:           absolute           base_tsc          base_nano
  Uptime  : 0x0000050de962eb77
  Sleep   : 0x00000360d7e59ac6 0x0000819188b511fa 0x0000035e0cc98a3f
  Wake    : 0x000003610ac134ae 0x000081dd606e7b8c 0x00000360e9e6e12e
last started kext at 5485587191614: >usb.cdc.acm	5.0.0 (addr 0xffffff7fb6fa2000, size 8192)
last stopped kext at 4030580153044: >usb.serial	6.0.0 (addr 0xffffff7fb700c000, size 20480)
Posted by
accm
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I'm also seeing constant kernel panics when connecting/disconnecting my monitors. I have a 2021 16" MacBook Pro (2019 model, 2.3 GHz 8-Core Intel Core i9, 32 GB 2667 MHz DDR4, Intel UHD Graphics 630 1536 M😎 and am running Big Sur 11.3.1. The machine is only a couple of weeks old and I can easily reproduce the problem by simply connecting and disconnecting the monitor cable 2 or 3 times.

I initially thought the problem was my CalDigit TS3 Plus but I started to remove all peripherals to see what was causing the problem and eventually got to a single monitor (Dell U2415) and a single USB-C to DisplayPort cable - no dock or hub involved. I disconnected keyboard, trackpad, headphones, yubi key, etc etc. I even booted in safe mode but issue persists.

My crash report is the same as reported by most folks in this thread: panic(cpu 0 caller 0xffffff801d69f6b6): [kext.kalloc.2048]: element modified after free (off:1672, val:0xfffffffe00000000, sz:2048, ptr:0xffffff93926d4000, prot:zero)

The interesting bit I found was that everything works fine if I connect my monitors via HDMI rather than DisplayPort. So at the moment I have 2 external monitor connected via USB-C to HDMI cables (1 using the TS3 dock, and 1 using a cheap USB hub).

Posted by
scarvalhojr
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  • My employer has sent me another brand new laptop, exact same model and specs. I turned it on, typed my password and plugged in my monitor with an USB-C to DisplayPort cable. I disconnected the cable and reconnected it 3 or 4 times and... boom! Laptop crashed. I rebooted it and did the same thing again and got another kernel panic. I was hoping my previous (2 week old) laptop had some sort of hardware issue but it looks like this is a pretty consistent and ubiquitous bug.

    The only difference between the new laptop and the previous one is that the new one is running Catalina 10.15.7 and the previous one is running Big Sur 11.3.1. Given that 2 brand new laptops running widely different macOS versions are crashing straight out of the box, I suspect this must be hurting a lot of people out there.

    —
    scarvalhojr

  • @scarvalhojr

    On catalina your kernel panic will be a little bit different. I've had this issue on Catalina and opened a case about it with Apple support. The issue was then fixed with Big Sur. Only to reappear in a different way (different kernel panic) with 11.3. See also this reddit post where someone found this kernel panic during beta testing: https://www.reddit.com/r/MacOSBeta/comments/mpcd54/macos_11_113_beta_7/

    The Catalina kernel panic was:

    panic(cpu 6 caller 0xffffff801cb27998): "kfree: size 4539647261356396544 > kalloc_largest_allocated 16302080"@/AppleInternal/BuildRoot/Library/Caches/com.apple.xbs/Sources/xnu/xnu-6153.141.1/osfmk/kern/kalloc.c:868 B

    —
    DelGurth

  • @scarvalhojr I’ve tested this issue with a different model 2019 16” macbook pro. The cheaper model without the AMD Radeon Pro 5500M in it. I was not able to crash that one. Those laptops you had this issue with, did they have the extra video card option as well?

    —
    DelGurth
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Reproduced in macOS 12 Monterey 🤦‍♂️

Posted by
trukhinyuri
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Every day this machine crashes, a top of the line 16" MBP. Now in Monterey?? 

Posted by
bromax6000
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Mine still crashes aswell, everyday after waking up, high fan, dead. restart with Errors.

I called Belkin Support, they told me they are aware of that Problem and it only appears on Big Sur. They can't do anything as the Device has no Firmware. It's totally up to Apple.

Posted by
daanse
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Same issue here for months, same two monitors or mostly after other monitors connected, eg TV in mtg room. Sometime just turning monitors on/off or unplugging/plugin the cable again. Also in 11.4 😦

Posted by
sftroels
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Belkin has official Announcement about Macbook Pros 2019 - 2020: https://www.belkin.com/de/support-article?articleNum=318353

Posted by
daanse
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I have had the same problem on Big Sur using a Dell WD19TB Thunderbolt Docking Station.

 1584: 0x0000210100000000
 1592: 0x0000000b00005400
 1600: 0x0000000000000009
 1608: 0x0000020300000100
 1616: 0x0000015400000154
 1624: 0x0000000100000a00
 1632: 0x000008340000041a
 1640: 0x0000000000001400
Backtrace (CPU 10), Frame : Return Address
0xffffffa0d3562cf0 : 0xffffff8009a8e0dd 
0xffffffa0d3562d40 : 0xffffff8009bd4f33 
0xffffffa0d3562d80 : 0xffffff8009bc552a 
0xffffffa0d3562dd0 : 0xffffff8009a32a2f 
0xffffffa0d3562df0 : 0xffffff8009a8d8fd 
0xffffffa0d3562f10 : 0xffffff8009a8dbf3 
0xffffffa0d3562f80 : 0xffffff800a29d81a 
0xffffffa0d3562ff0 : 0xffffff800a29f846 
0xffffffa0d3563470 : 0xffffff8009aecad6 
0xffffffa0d35634e0 : 0xffffff8009a9d6bc 
0xffffffa0d3563530 : 0xffffff800a1ae4f2 
0xffffffa0d3563550 : 0xffffff7fa3ef8fce 
0xffffffa0d3563600 : 0xffffff7fa3ef965e 
0xffffffa0d3563640 : 0xffffff7fa3eb9d86 
0xffffffa0d3563660 : 0xffffff7fa47f3e78 
0xffffffa0d3563900 : 0xffffff7fa3eba924 
0xffffffa0d3563930 : 0xffffff7fa47f5074 
0xffffffa0d35639c0 : 0xffffff7fa47f30f7 
0xffffffa0d3563a10 : 0xffffff7fa47f2ee7 
0xffffffa0d3563a60 : 0xffffff7fa47f1f99 
0xffffffa0d3563aa0 : 0xffffff800a21e13e 
0xffffffa0d3563af0 : 0xffffff7fa3eba5e2 
0xffffffa0d3563b20 : 0xffffff800a22837b 
0xffffffa0d3563c80 : 0xffffff8009b80961 
0xffffffa0d3563d90 : 0xffffff8009a9375d 
0xffffffa0d3563e00 : 0xffffff8009a69cf5 
0xffffffa0d3563e60 : 0xffffff8009a81312 
0xffffffa0d3563ef0 : 0xffffff8009ba982d 
0xffffffa0d3563fa0 : 0xffffff8009a33216 
      Kernel Extensions in backtrace:
         com.apple.iokit.IOAcceleratorFamily2(442.9)[BDA1401D-563F-3650-B616-C8073E90475B]@0xffffff7fa47ae000->0xffffff7fa4818fff
            dependency: com.apple.driver.AppleMobileFileIntegrity(1.0.5)[366C7BD4-9502-3D1C-ABBE-DE9749913D0C]@0xffffff800b0c0000->0xffffff800b0d5fff
            dependency: com.apple.iokit.IOGraphicsFamily(585.1)[2C81B74F-C771-3643-82EC-12CD4AC5EFDB]@0xffffff7fa492f000->0xffffff7fa495dfff
            dependency: com.apple.iokit.IOPCIFamily(2.9)[99A70889-A31C-3B25-8E88-ADD3F317E4E4]@0xffffff800c56a000->0xffffff800c592fff
            dependency: com.apple.iokit.IOReportFamily(47)[367CCAE7-DAB4-3424-B191-44044619D5CB]@0xffffff800c5a1000->0xffffff800c5a3fff
            dependency: com.apple.iokit.IOSurface(290.8.1)[8FA218E4-361C-3C8B-94F0-48434AA535A0]@0xffffff800c694000->0xffffff800c6b0fff
         com.apple.driver.AppleIntelKBLGraphics(16.0.4)[F7BCF586-AF08-3277-9C66-04F439E684B4]@0xffffff7fa3ea3000->0xffffff7fa3f5afff
            dependency: com.apple.iokit.IOAcceleratorFamily2(442.9)[BDA1401D-563F-3650-B616-C8073E90475B]@0xffffff7fa47ae000->0xffffff7fa4818fff
            dependency: com.apple.iokit.IOGraphicsFamily(585.1)[2C81B74F-C771-3643-82EC-12CD4AC5EFDB]@0xffffff7fa492f000->0xffffff7fa495dfff
            dependency: com.apple.iokit.IOPCIFamily(2.9)[99A70889-A31C-3B25-8E88-ADD3F317E4E4]@0xffffff800c56a000->0xffffff800c592fff
            dependency: com.apple.iokit.IOSurface(290.8.1)[8FA218E4-361C-3C8B-94F0-48434AA535A0]@0xffffff800c694000->0xffffff800c6b0fff

Process name corresponding to current thread: TouchBarServer
Boot args: chunklist-security-epoch=0 -chunklist-no-rev2-dev chunklist-security-epoch=0 -chunklist-no-rev2-dev

Mac OS version:
20F71

Kernel version:
Darwin Kernel Version 20.5.0: Sat May  8 05:10:33 PDT 2021; root:xnu-7195.121.3~9/RELEASE_X86_64
Kernel UUID: 52A1E876-863E-38E3-AC80-09BBAB13B752
KernelCache slide: 0x0000000009800000
KernelCache base:  0xffffff8009a00000
Kernel slide:      0x0000000009810000
Kernel text base:  0xffffff8009a10000
__HIB  text base: 0xffffff8009900000
System model name: MacBookPro16,1 (Mac-E1008331FDC96864)
System shutdown begun: NO
Hibernation exit count: 12

System uptime in nanoseconds: 44120622946291
Last Sleep:           absolute           base_tsc          base_nano
  Uptime  : 0x00002820a20edafc
  Sleep   : 0x0000281a9b5f8e9a 0x0000000201beb7d4 0x0000280af830fca7
  Wake    : 0x0000281abf2d9789 0x0000000200a50fbc 0x0000281aaa3beba3
last started kext at 14175647796: >AGPM	122.1 (addr 0xffffff7fa31a3000, size 118784)
loaded kexts:
Posted by
technetium-43
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Dear Apple Support & Engineers

The is simply unacceptable. I get 2 crashes per day!!!

I first reported this 2 months ago, after the first crash, right after the update to Big Sur 11.3 Then updated to 11.4 hoping it would fix it? Of course, it didn't.

The issue is with osX. I tried 5 different docks, my CalDigit and 4 that I borrowed from colleagues at the office (CalDigit, HP, StartTech, some no-name from Amazon & Microsoft one), all having the same problem with I connect my MacBook Pro 16 (it's less than 9 month old!!) - it crashes within 10 seconds of connecting to dock. I have to reboot it.

The crash report is different every time too? See attached samples from the past few weeks

RIDICULOUS!!

  1. crash_report_202106220852.txt
  2. crash_report_202106161018.txt
  3. crash_report_202106160010.txt
  4. crash_report_202005101310.txt
  5. crash_report_202005061010.txt
Posted by
kinvoki
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  • Have you tried connecting monitors directly to the laptop instead of via docks? Also, try a HDMI connection instead of DisplayPort if you can. In my case I found out the problem is not the dock but rather connecting/disconnecting a DisplayPort cable.

    —
    scarvalhojr

  • It is definitely tied to connecting a cable after disconnecting it. I can make it crash like clock work by doing so.

    —
    MichaelClayton79
Add a Comment

This is getting ridiculous, I keep getting interrupted in my work because of this. Apple what are you doing ? You still have to support the intel based hardware !!

Posted by
syl20bnr
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@apple can you please take this seriously.

This has been going for months - many threads in apple developer, reddit, news articles, etc but still no fix. I'm on big sur 11.4, this problem always happens when connecting to dock.

Submitted to APPLE so many times.

Details:

MacBook Pro (16-inch, 2019) 2.6 GHz 6-Core Intel Core i7 AMD Radeon Pro 5300M 4 GB Intel UHD Graphics 630 1536 MB

panic(cpu 4 caller 0xffffff8013a9f846): [kext.kalloc.2048]: element modified after free (off:1672, val:0xffffffff00000000, sz:2048, ptr:0xffffff9372beb000, prot:zero) 1672: 0xffffffff00000000 Backtrace (CPU 4), Frame : Return Address 0xffffffa0c6882c10 : 0xffffff801328e0dd .... Kernel Extensions in backtrace: com.apple.kext.AMDRadeonX6000Framebuffer(4.0.5)[57D9B457-0E07-3304-B3E5-2D05A3E6FB13]@0xffffff7fa1ef6000->0xffffff7fa2170fff dependency: com.apple.AppleGraphicsDeviceControl(6.3.3)[6E0CE02A-0480-3500-9A25-9CD277522DF9]@0xffffff7fac94a000->0xffffff7fac94dfff dependency: com.apple.iokit.IOACPIFamily(1.4) .... Process name corresponding to current thread: kernel_task Boot args: chunklist-security-epoch=0 -chunklist-no-rev2-dev chunklist-security-epoch=0 -chunklist-no-rev2-dev

Mac OS version: 20F71

Kernel version: Darwin Kernel Version 20.5.0: Sat May 8 05:10:33 PDT 2021; root:xnu-7195.121.3~9/RELEASE_X86_64

Posted by
kent-id
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  • Have you tried connecting monitors directly to the laptop instead of via dock? Also, try a HDMI connection instead of DisplayPort if you can. In my case I found out the problem is not the dock but rather connecting/disconnecting a DisplayPort cable.

    —
    scarvalhojr
Add a Comment

Hi all, found this thread by googling the first line of my crash report.

I am getting the exact same issue (16", 11.4) only I am using the Pluggable TBT3-UDZ TB3 dock.

The issue seemed to be related often to one of my external monitors turning on/off or the cables being plugged in or out. I'd get the fan whir and a crash out to restart. It sometime happened when the dock itself was plugged in or out (which would of course include the monitors disconnecting). The only time it happened when I left the dock connected was when the monitors were doing something.

Switching to the HDMI ports on the dock from DP (this dock offers the choice of DP or HDMI for both of it's outputs thankfully) seems to have fixed the issue. My guess is that it is related to the signal that Display port sends back to the computer (called EDID?) to tell it whether the monitor is switched on or not. On DP, if I turned a monitor off it would blank out the other displays for a moment and rejig the arrangement in settings. With HDMI, turning the monitor off doesn't do this and the monitor is still listed in settings.

Hopefully that helps someone else out until apple pull their socks up!

Richard.

Posted by
Richard_Costin
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  • Same thing happened to me. I've switched to HDMI and haven't had any crashes for the last 2 weeks. In my case it's definitely a problem with DisplayPort. In fact, I can reproduce it with a single monitor and a single USB-C to DisplayPort cable (no docks or hubs involved). Plug it in and out and boom. I've upgraded from Big Sur 11.31. to 11.4 this week and can confirm the bug is still there.

    I hope Apple fixes this soon as my dock (CalDigit TS3 Plus, bought through Apple by the way!) only has one Thunderbolt port so I can only connect a single monitor via HDMI - the other monitor port is a DisplayPort so I'm having to use a second adapter to connect the other monitor to avoid crashing my laptop, which totally defeats the purpose of buying an expensive dock in the first place!

    —
    scarvalhojr
Add a Comment

Unfortunately no answer here, just here to tell that I'm experiencing the same and know how to reproduce it without even using a dock. I need to connect my Dell monitor via USB-C on one of the 2 DisplayPort connections on the monitor. Then I need to turn the display on and off and then it will crash (not all the time, but quite soon).

I've raised a call with Apple Support about this. But apple claims it's a problem with my hardware and not with their software. So now I need to visit a service center to proof that it's their software and not my hardware that is causing the issue.

Posted by
DelGurth
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  • I had my MacBook at the local Apple Store just recently for a couple of days and they checked it through (after wiping and resetting it). They returned it to me and said there is no hardware and/or software problem with the device. So according to them it must be either a) a problem of some software that I have installed or b) a problem with some external hardware. If it's not reproducible without any external hardware connected or 3rd party software installed they will always claim that it's not "their fault". What is strange in my case is that I've never had this one panic before (but other ones, that's why I brought it to the Apple Store - and spent countless hours trying all kind of other things before), but this error ("element modified after free") now happens after I got it back from the Apple Store, when I plug in a specific external USB-C hub with one or two monitors connected. It looks like it happens more often if I connect it right after waking the MacBook up from sleep.

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    klemensz

  • @klemensz yeah, the support engineer assigned to my case also claims it not on their end. But my 15" MacBook with the same macOS version works just fine. And I can even trigger the issue from Safe mode, so no local modifications possible (it's a bit harder to trigger from safe mode, it happens less frequently then when the os is actually running with software).

    The reason I frequently ran into this issue is that I had my audio connected via displayPort and the audio does not work after waking from sleep. I just connected the audio directly in the MacBook and now I no longer have to turn my displays off an on again to regain my audio, so no more crashes. For me it doesn't crash after waking from sleep.

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    DelGurth

  • What Apple is claiming is absolute nonsense. I'm experiencing this issue with a brand new 16" MBP 2019 model. My employer sent me another machine, exact same specs and problem was still there! I reformatted it and did a clean install of Mojave, same problem. Upgraded to Big Sur, same. Both machines, brand new, crashing with a single monitor using USB-C to DisplayPort cable. No hubs/docks. They also crash when booted in safe mode. It's dead simple to reproduce.

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    scarvalhojr
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