iMac Unexpectedly Crashing/Restarting

Hi Everyone -

My 27" iMac keeps crashing, but I am unable to figure out what the cause is. Here is the system report, but i don’t know how to understand/interpret - would anyone be able to help me out?

*** Panic Report ***
panic(cpu 1 caller 0xffffff801e2b09a5): “Invalid queue element linkage for 0xffffff8724e085a0: next 0xffffff80b1f50520 next->prev 0 prev 0xffffff80bb4fd780 prev->next 0xffffff8724e085a0”@/BuildRoot/Library/Caches/com.apple.xbs/Sources/xnu/xnu-4570.71.2/osfmk/kern/queue.h:245
Backtrace (CPU 1), Frame : Return Address
0xffffffa7634a3190 : 0xffffff801e26c1c6
0xffffffa7634a31e0 : 0xffffff801e395274
0xffffffa7634a3220 : 0xffffff801e387544
0xffffffa7634a3290 : 0xffffff801e21e1e0
0xffffffa7634a32b0 : 0xffffff801e26bc3c
0xffffffa7634a33e0 : 0xffffff801e26b9fc
0xffffffa7634a3440 : 0xffffff801e2b09a5
0xffffffa7634a34b0 : 0xffffff801e2b4f4b
0xffffffa7634a3500 : 0xffffff801e285bf1
0xffffffa7634a3530 : 0xffffff801e27b4ce
0xffffffa7634a3570 : 0xffffff801e72f8e6
0xffffffa7634a35f0 : 0xffffff801e4816db
0xffffffa7634a3630 : 0xffffff7fa06776a7
0xffffffa7634a36d0 : 0xffffff7fa06786f8
0xffffffa7634a36f0 : 0xffffff7fa0679df5
0xffffffa7634a37c0 : 0xffffff7fa066ea41
0xffffffa7634a3d60 : 0xffffff801e4ce726
0xffffffa7634a3de0 : 0xffffff801e4b5844
0xffffffa7634a3f10 : 0xffffff801e4b5a77
0xffffffa7634a3f40 : 0xffffff801e803968
0xffffffa7634a3fa0 : 0xffffff801e21e9c6
Kernel Extensions in backtrace:
com.apple.filesystems.hfs.kext(407.50.6)[09445723-F283-31E5-B409-43D905BA81C6]@0xffffff7fa0668000->0xffffff7fa06cefff
dependency: com.apple.filesystems.hfs.encodings.kext(1)[F737F125-223E-3B67-B4FF-5AB56291D4FE]@0xffffff7fa0660000

BSD process name corresponding to current thread: bzfilelist

Mac OS version:
17G65

Kernel version:
Darwin Kernel Version 17.7.0: Thu Jun 21 22:53:14 PDT 2018; root:xnu-4570.71.2~1/RELEASE_X86_64
Kernel UUID: 1AE5ACFD-3B6F-3D74-AD52-31F1430DBC6F
Kernel slide: 0x000000001e000000
Kernel text base: 0xffffff801e200000
__HIB text base: 0xffffff801e100000
System model name: iMac17,1 (Mac-DB15BD556843C820)

System uptime in nanoseconds: 311890757592
last loaded kext at 25828912630: com.apple.driver.AppleHIDKeyboard 205 (addr 0xffffff7fa08de000, size 45056)
loaded kexts:
com.apple.driver.AppleTopCaseHIDEventDriver 133
com.apple.driver.AudioAUUC 1.70
com.apple.driver.ApplePlatformEnabler 2.7.0d0
com.apple.driver.AGPM 110.23.37
com.apple.driver.X86PlatformShim 1.0.0
com.apple.filesystems.autofs 3.0
com.apple.driver.AppleMikeyHIDDriver 131
com.apple.driver.AppleMikeyDriver 281.52
com.apple.driver.AppleUpstreamUserClient 3.6.5
com.apple.kext.AMDFramebuffer 1.6.8
com.apple.driver.AppleHDAHardwareConfigDriver 281.52
com.apple.kext.AMDRadeonX4000 1.6.8
com.apple.driver.AppleHDA 281.52
com.apple.driver.AppleGraphicsDevicePolicy 3.20.13
com.apple.AGDCPluginDisplayMetrics 3.20.13
com.apple.driver.pmtelemetry 1
com.apple.iokit.IOUserEthernet 1.0.1
com.apple.iokit.IOBluetoothSerialManager 6.0.7f10
com.apple.Dont_Steal_Mac_OS_X 7.0.0
com.apple.driver.AppleHV 1
com.apple.driver.AppleIntelSKLGraphics 10.3.6
com.apple.driver.AppleIntelPCHPMC 2.0.1
com.apple.driver.AppleThunderboltIP 3.1.1
com.apple.iokit.BroadcomBluetooth20703USBTransport 6.0.7f10
com.apple.driver.eficheck 1
com.apple.kext.AMD7000Controller 1.6.8
com.apple.driver.AppleIntelSKLGraphicsFramebuffer 10.3.6
com.apple.driver.AppleSMCLMU 211
com.apple.driver.AppleOSXWatchdog 1
com.apple.driver.AppleIntelSlowAdaptiveClocking 4.0.0
com.apple.driver.AppleFIVRDriver 4.1.0
com.apple.driver.ACPI_SMC_PlatformPlugin 1.0.0
com.apple.driver.AGDCBacklightControl 3.20.13
com.apple.driver.AppleBacklight 170.12.6
com.apple.driver.AppleMCCSControl 1.5.5
com.apple.iokit.IOBluetoothUSBDFU 6.0.7f10
com.apple.iokit.SCSITaskUserClient 404.30.2
com.apple.driver.AppleUSBStorageCoexistentDriver 439.70.3
com.apple.driver.CoreStorageFsck 546.50.1
com.apple.driver.AppleFileSystemDriver 3.0.1
com.apple.AppleFSCompression.AppleFSCompressionTypeDataless 1.0.0d1
com.apple.AppleFSCompression.AppleFSCompressionTypeZlib 1.0.0
com.apple.AppleSystemPolicy 1.0
com.apple.BootCache 40
com.apple.filesystems.hfs.kext 407.50.6
com.apple.driver.AirPort.BrcmNIC 1241.31.1a9
com.apple.driver.AppleSDXC 1.7.6
com.apple.iokit.AppleBCM5701Ethernet 10.3.1
com.apple.filesystems.apfs 748.51.0
com.apple.driver.AppleAHCIPort 329.50.2
com.apple.driver.AppleRTC 2.0
com.apple.driver.AppleACPIButtons 6.1
com.apple.driver.AppleHPET 1.8
com.apple.driver.AppleSMBIOS 2.1
com.apple.driver.AppleACPIEC 6.1
com.apple.driver.AppleAPIC 1.7
com.apple.nke.applicationfirewall 183
com.apple.security.quarantine 3
com.apple.security.TMSafetyNet 8
com.apple.driver.AppleHIDKeyboard 205
com.apple.driver.AppleActuatorDriver 1404.4
com.apple.driver.AppleMultitouchDriver 1404.4
com.apple.driver.AppleInputDeviceSupport 1404.3
com.apple.driver.AppleHSBluetoothDriver 133
com.apple.driver.IOBluetoothHIDDriver 6.0.7f10
com.apple.kext.triggers 1.0
com.apple.kext.AMDRadeonX4030HWLibs 1.0
com.apple.driver.DspFuncLib 281.52
com.apple.kext.OSvKernDSPLib 526
com.apple.kext.AMDRadeonX4000HWServices 1.6.8
com.apple.driver.AppleGraphicsControl 3.20.13
com.apple.iokit.IOSerialFamily 11
com.apple.iokit.IOAVBFamily 680.2
com.apple.plugin.IOgPTPPlugin 680.15
com.apple.driver.AppleSSE 1.0
com.apple.AppleGPUWrangler 3.20.13
com.apple.driver.AppleThunderboltEDMSink 4.1.4
com.apple.iokit.BroadcomBluetoothHostControllerUSBTransport 6.0.7f10
com.apple.iokit.IOBluetoothHostControllerUSBTransport 6.0.7f10
com.apple.iokit.IOBluetoothHostControllerTransport 6.0.7f10
com.apple.iokit.IOBluetoothFamily 6.0.7f10
com.apple.kext.AMDSupport 1.6.8
com.apple.iokit.IOAcceleratorFamily2 378.26
com.apple.iokit.IOSurface 211.15
com.apple.driver.AppleHDAController 281.52
com.apple.iokit.IOHDAFamily 281.52
com.apple.iokit.IOAudioFamily 206.5
com.apple.vecLib.kext 1.2.0
com.apple.driver.AppleSMBusPCI 1.0.14d1
com.apple.iokit.IOSlowAdaptiveClockingFamily 1.0.0
com.apple.driver.IOPlatformPluginLegacy 1.0.0
com.apple.driver.X86PlatformPlugin 1.0.0
com.apple.driver.IOPlatformPluginFamily 6.0.0d8
com.apple.AppleGraphicsDeviceControl 3.20.13
com.apple.driver.AppleBacklightExpert 1.1.0
com.apple.iokit.IONDRVSupport 519.20
com.apple.driver.AppleSMBusController 1.0.18d1
com.apple.iokit.IOGraphicsFamily 519.20
com.apple.driver.usb.IOUSBHostHIDDevice 1.2
com.apple.iokit.IOUSBMassStorageClass 4.0.4
com.apple.driver.usb.cdc 5.0.0
com.apple.driver.usb.networking 5.0.0
com.apple.driver.usb.AppleUSBHub 1.2
com.apple.driver.usb.AppleUSBHostCompositeDevice 1.2
com.apple.driver.CoreStorage 546.50.1
com.apple.filesystems.hfs.encodings.kext 1
com.apple.driver.AppleThunderboltDPInAdapter 5.5.5
com.apple.driver.AppleThunderboltDPOutAdapter 5.5.5
com.apple.driver.AppleThunderboltDPAdapterFamily 5.5.5
com.apple.driver.AppleThunderboltPCIDownAdapter 2.1.3
com.apple.driver.AppleThunderboltNHI 4.7.2
com.apple.iokit.IOThunderboltFamily 6.7.8
com.apple.iokit.IO80211Family 1200.12.2
com.apple.driver.corecapture 1.0.4
com.apple.iokit.IOEthernetAVBController 1.1.0
com.apple.driver.mDNSOffloadUserClient 1.0.1b8
com.apple.iokit.IONVMeFamily 2.1.0
com.apple.driver.AppleIntelLpssI2C 3.0.60
com.apple.driver.AppleXsanScheme 3
com.apple.iokit.IOAHCIBlockStorage 301.40.2
com.apple.driver.AppleUSBMergeNub 900.4.1
com.apple.driver.AppleUSBHostMergeProperties 1.2
com.apple.driver.usb.AppleUSBHostPacketFilter 1.0
com.apple.driver.AppleIntelLpssGspi 3.0.60
com.apple.iokit.IOUSBFamily 900.4.1
com.apple.driver.usb.AppleUSBXHCIPCI 1.2
com.apple.driver.usb.AppleUSBXHCI 1.2
com.apple.iokit.IOAHCIFamily 288
com.apple.driver.AppleEFINVRAM 2.1
com.apple.driver.AppleEFIRuntime 2.1
com.apple.iokit.IOSMBusFamily 1.1
com.apple.iokit.IOHIDFamily 2.0.0
com.apple.security.sandbox 300.0
com.apple.kext.AppleMatch 1.0.0d1
com.apple.driver.AppleFDEKeyStore 28.30
com.apple.driver.AppleEffaceableStorage 1.0
com.apple.driver.AppleKeyStore 2
com.apple.driver.AppleUSBTDM 439.70.3
com.apple.driver.AppleMobileFileIntegrity 1.0.5
com.apple.iokit.IOUSBMassStorageDriver 140.70.2
com.apple.iokit.IOSCSIBlockCommandsDevice 404.30.2
com.apple.iokit.IOSCSIArchitectureModelFamily 404.30.2
com.apple.driver.AppleCredentialManager 1.0
com.apple.driver.KernelRelayHost 1
com.apple.iokit.IOUSBHostFamily 1.2
com.apple.driver.usb.AppleUSBCommon 1.0
com.apple.driver.AppleBusPowerController 1.0
com.apple.driver.AppleSEPManager 1.0.1
com.apple.driver.IOSlaveProcessor 1
com.apple.driver.DiskImages 480.60.1
com.apple.iokit.IOStorageFamily 2.1
com.apple.iokit.IOReportFamily 31
com.apple.iokit.IOTimeSyncFamily 680.15
com.apple.iokit.IONetworkingFamily 3.4
com.apple.driver.AppleACPIPlatform 6.1
com.apple.driver.AppleSMC 3.1.9
com.apple.iokit.IOPCIFamily 2.9
com.apple.iokit.IOACPIFamily 1.4
com.apple.kec.Libm 1
com.apple.kec.pthread 1
com.apple.kec.corecrypto 1.0

EOF

System Profile:
Network Service: Wi-Fi, AirPort, en1
Thunderbolt Bus: iMac, Apple Inc., 28.1
Boot Volume File System Type: hfs
Memory Module: BANK 0/DIMM0, 16 GB, DDR3, 1867 MHz, 0x00, -
Memory Module: BANK 0/DIMM1, 16 GB, DDR3, 1867 MHz, 0x00, -
Memory Module: BANK 1/DIMM0, 16 GB, DDR3, 1867 MHz, 0x00, -
Memory Module: BANK 1/DIMM1, 16 GB, DDR3, 1867 MHz, 0x00, -
USB Device: USB 3.0 Bus
USB Device: My Passport 259D
USB Device: My Passport 259F
USB Device: USB3.0 Hub
USB Device: Backup+ Hub
USB Device: Backup+ Hub WH
USB Device: USB2.0 Hub
USB Device: Bluetooth USB Host Controller
USB Device: FaceTime HD Camera (Built-in)
USB Device: Backup+ Hub
Serial ATA Device: APPLE HDD ST1000DM003, 1 TB
Model: iMac17,1, BootROM IM171.0157.B00, 4 processors, Intel Core i5, 3.2 GHz, 64 GB, SMC 2.33f10
Graphics: AMD Radeon R9 M390, AMD Radeon R9 M390, PCIe
AirPort: spairport_wireless_card_type_airport_extreme (0x14E4, 0x14A), Broadcom BCM43xx 1.0 (7.77.37.31.1a9)
Bluetooth: Version 6.0.7f10, 3 services, 27 devices, 1 incoming serial ports
Model: iMac17,1, BootROM IM171.0157.B00, 4 processors, Intel Core i5, 3.2 GHz, 64 GB, SMC 2.33f10
Graphics: AMD Radeon R9 M390, AMD Radeon R9 M390, PCIe
Memory Module: BANK 0/DIMM0, 16 GB, DDR3, 1867 MHz, 0x00, -
Memory Module: BANK 0/DIMM1, 16 GB, DDR3, 1867 MHz, 0x00, -
Memory Module: BANK 1/DIMM0, 16 GB, DDR3, 1867 MHz, 0x00, -
Memory Module: BANK 1/DIMM1, 16 GB, DDR3, 1867 MHz, 0x00, -
AirPort: spairport_wireless_card_type_airport_extreme (0x14E4, 0x14A), Broadcom BCM43xx 1.0 (7.77.37.31.1a9)
Bluetooth: Version 6.0.7f10, 3 services, 27 devices, 1 incoming serial ports
Network Service: Wi-Fi, AirPort, en1
Serial ATA Device: APPLE HDD ST1000DM003, 1 TB
USB Device: USB 3.0 Bus
USB Device: My Passport 259D
USB Device: My Passport 259F
USB Device: USB3.0 Hub
USB Device: Backup+ Hub
USB Device: Backup+ Hub WH
USB Device: USB2.0 Hub
USB Device: Bluetooth USB Host Controller
USB Device: FaceTime HD Camera (Built-in)
USB Device: Backup+ Hub
Thunderbolt Bus: iMac, Apple Inc., 28.1

I had the same issue. I spent months on and off on calls with Apple Support and even taking it in to the store a bunch of times. They eventually discovered that there was something wrong with the RAM. Hopefully, that isn’t the case for you. Try all of the RAM resets https://www.macworld.com/article/2881177/macs/how-to-reset-your-macs-nvram-pram-and-smc.html

Does the fan spin up before it crashes?

Just trying to the read the plain text in your output seems to be pointing to bzfilelist which I believe is a part of Backblaze. Maybe try booting into safe mode (hit the power on and hold down shift until you see the apple logo) and see if it boots okay. If so, maybe try uninstalling and reinstalling Backblaze.

I may be way off, this is just a guess based on that current thread, but worth a shot. Safe mode in general cleans up a lot of caches which can help with a lot of issues.

No it doesn’t. There are no signs leading up to when it happens.

It appears that the RAM resets worked. No crashes yet - fingers crossed. But if that does not work I will try the safe mode/backblaze/reinstall solution.

Curious, did you have to have your ram replaced?

I installed 64 gb of 3rd party ram (owc) when I bought this iMac.

Thank you for your help as always!!!

@James_Flores I had these issues with the original RAM not a third party replacement.

But, yes I did end up having to get the RAM replaced.

The ram resets only worked temporarily.

So I am now going through the process of installing each stick of ram individually to see which one is faulty/causes a crash.