The problem still exists with macOS 11.4, when connect with my CalDigit USB-C Pro Dock. panic(cpu 6 caller 0xffffff800509f846): [kext.kalloc.2048]: element modified after free (off:1672, val:0xfffffffe00000000, sz:2048, ptr:0xffffff9363ace800, prot:zero) 1672: 0xfffffffe00000000 Backtrace (CPU 6), Frame : Return Address 0xffffffb0cfbdacf0 : 0xffffff800488e0dd 0xffffffb0cfbdad40 : 0xffffff80049d4f33 0xffffffb0cfbdad80 : 0xffffff80049c552a 0xffffffb0cfbdadd0 : 0xffffff8004832a2f 0xffffffb0cfbdadf0 : 0xffffff800488d8fd 0xffffffb0cfbdaf10 : 0xffffff800488dbf3 0xffffffb0cfbdaf80 : 0xffffff800509d81a 0xffffffb0cfbdaff0 : 0xffffff800509f846 0xffffffb0cfbdb470 : 0xffffff80048ecad6 0xffffffb0cfbdb4e0 : 0xffffff800489d6bc 0xffffffb0cfbdb530 : 0xffffff8004fae4f2 0xffffffb0cfbdb550 : 0xffffff7f9ecf8fce 0xffffffb0cfbdb600 : 0xffffff7f9ecf965e 0xffffffb0cfbdb640 : 0xffffff7f9ecb9d86 0xffffffb0cfbdb660 : 0xffffff7f9f5f3e78 0xffffffb0cfbdb900 : 0xffffff7f9ecba924 0xffffffb0cfbdb930 : 0xffffff7f9f5f5074 0xffffffb0cfbdb9c0 : 0xffffff7f9f5f30f7 0xffffffb0cfbdba10 : 0xffffff7f9f5f2ee7 0xffffffb0cfbdba60 : 0xffffff7f9f5f1f99 0xffffffb0cfbdbaa0 : 0xffffff800501e13e 0xffffffb0cfbdbaf0 : 0xffffff7f9ecba5e2 0xffffffb0cfbdbb20 : 0xffffff800502837b 0xffffffb0cfbdbc80 : 0xffffff8004980961 0xffffffb0cfbdbd90 : 0xffffff800489375d 0xffffffb0cfbdbe00 : 0xffffff8004869cf5 0xffffffb0cfbdbe60 : 0xffffff8004881312 0xffffffb0cfbdbef0 : 0xffffff80049a982d 0xffffffb0cfbdbfa0 : 0xffffff8004833216 Kernel Extensions in backtrace: com.apple.iokit.IOAcceleratorFamily2(442.9)[BDA1401D-563F-3650-B616-C8073E90475B]@0xffffff7f9f5ae000->0xffffff7f9f618fff dependency: com.apple.driver.AppleMobileFileIntegrity(1.0.5)[366C7BD4-9502-3D1C-ABBE-DE9749913D0C]@0xffffff8005ec0000->0xffffff8005ed5fff dependency: com.apple.iokit.IOGraphicsFamily(585.1)[2C81B74F-C771-3643-82EC-12CD4AC5EFDB]@0xffffff7f9f72f000->0xffffff7f9f75dfff dependency: com.apple.iokit.IOPCIFamily(2.9)[99A70889-A31C-3B25-8E88-ADD3F317E4E4]@0xffffff800736a000->0xffffff8007392fff dependency: com.apple.iokit.IOReportFamily(47)[367CCAE7-DAB4-3424-B191-44044619D5CB]@0xffffff80073a1000->0xffffff80073a3fff dependency: com.apple.iokit.IOSurface(290.8.1)[8FA218E4-361C-3C8B-94F0-48434AA535A0]@0xffffff8007494000->0xffffff80074b0fff com.apple.driver.AppleIntelKBLGraphics(16.0.4)[F7BCF586-AF08-3277-9C66-04F439E684B4]@0xffffff7f9eca3000->0xffffff7f9ed5afff dependency: com.apple.iokit.IOAcceleratorFamily2(442.9)[BDA1401D-563F-3650-B616-C8073E90475B]@0xffffff7f9f5ae000->0xffffff7f9f618fff dependency: com.apple.iokit.IOGraphicsFamily(585.1)[2C81B74F-C771-3643-82EC-12CD4AC5EFDB]@0xffffff7f9f72f000->0xffffff7f9f75dfff dependency: com.apple.iokit.IOPCIFamily(2.9)[99A70889-A31C-3B25-8E88-ADD3F317E4E4]@0xffffff800736a000->0xffffff8007392fff dependency: com.apple.iokit.IOSurface(290.8.1)[8FA218E4-361C-3C8B-94F0-48434AA535A0]@0xffffff8007494000->0xffffff80074b0fff Process name corresponding to current thread: TouchBarServer 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: 0x0000000004600000 KernelCache base: 0xffffff8004800000 Kernel slide: 0x0000000004610000 Kernel text base: 0xffffff8004810000 __HIB text base: 0xffffff8004700000 System model name: MacBookPro16,1 (Mac-E1008331FDC96864) System shutdown begun: NO Hibernation exit count: 0