I'm experiencing an unusual problem that is affecting many of the apps I use on a regular basis, including (but not limited to): Adobe Illustrator CC 2019, Sublime Text 3, FileZilla, and even Apple's native TextEdit! The sequence of events goes something like this:

  1. An app freezes and I must Force Quit out of it.
  2. I try to re-launch the app, but the icon just bounces in the Dock endlessly (until I Force Quit again)
  3. I try to Shut Down the Mac, but macOS insists it can't shut down because said app is still running (although it shouldn't be, since I did a Force Quit). Also, no dot is shown below the app's Dock icon, leading one to believe it is not open, but it's still running.
  4. I must physically hold the power button to shut down.

^ As you can see, the application is "Not Responding". But there is no dot below to indicate it is even open to begin with.

I have tried to Force Quit the app(s) in question via Terminal as well, after identifying their Process IDs. Unfortunately, this has not worked either.

Further Details

macOS is the most current version to date: Mojave 10.14.2

This iMac shipped with High Sierra and I immediately updated it to Mojave before beginning to use it. This problem came to my attention after less than 1 month of use. I updated Mojave to 10.14.2 hoping it would fix the problem, however the problem persists. The Mac is just over 2 months old.

Freezing/hanging often often occurs upon saving a file. The file gets saved, but immediately after that the app (whichever app it is) becomes unusable. The problem seems to be closely tied to the file system.

^ It is usually right after saving a file that problems begin.

This is a work machine, and one other employee at the company is experiencing the same issue with Mojave (on an older Mac). We both connect to the company LAN, and do Time Machine backups over the LAN.

According to Disk Utility, nothing appears to be wrong with Macintosh HD:

Running First Aid on “Macintosh HD” (disk2s1)

NOTE: First Aid will temporarily lock the startup volume.

Verifying file system.
Volume could not be unmounted.
Using live mode.
Performing fsck_apfs -n -l -x /dev/rdisk2s1
Checking the container superblock.
Checking the fusion superblock.
Checking the EFI jumpstart record.
Checking the space manager.
Checking the space manager free queue trees.
Checking the object map.
Checking the Fusion data structures.
Checking volume.
Checking the APFS volume superblock.
The volume Macintosh HD was formatted by hfs_convert (945.200.129) and last modified by apfs_kext (945.230.6).
Checking the object map.
Checking the snapshot metadata tree.
Checking the snapshot metadata.
Checking snapshot 1 of 2.
Checking snapshot 2 of 2.
Checking the extent ref tree.
Checking the fsroot tree.
Verifying allocated space.
Performing deferred repairs.
The volume /dev/rdisk2s1 appears to be OK.
File system check exit code is 0.

Operation successful.

Crash report comparison

There's a lot of data to sort through, in crashes for multiple applications, so while it's hard to know what exactly to look for, the following lines look like they might provide a clue.

I used Compare Side-By-Side in Sublime Text. Text highlighted in darker pink and darker green is dissimilar. Text highlighted in lighter pink and lighter green is similar. White text is identical.

Crash log comparison showing a pattern with process diskarbitrationd [67]

Here's more information from the log on the left side, which happens to be TextEdit, the third crash I experienced on 2019-01-29.

I will include the portion for processes diskarbitrationd [67] and diskimages-helper [2452] because there is a lot of correlation there with the FileZilla crash one day prior.

Process:         diskarbitrationd [67]
UUID:            6A57BB14-2FB6-3420-ABDA-429D1991CFE3
Path:            /usr/libexec/diskarbitrationd
Architecture:    x86_64
Parent:          launchd [1]
UID:             0
Sudden Term:     Tracked
Footprint:       2016 KB
Start time:      2019-01-29 09:26:56 +0900
End time:        2019-01-29 09:26:58 +0900
Num samples:     17 (1-17)
Note:            1 idle work queue thread omitted

  Thread 0x252              DispatchQueue 1           17 samples (1-17)         priority 31 (base 31)
  <thread QoS default (requested default), process sudden termination dirty, IO tier 0>
  17  start + 1 (libdyld.dylib + 93913) [0x7fff5cd86ed9] 1-17
    17  ??? (diskarbitrationd + 29299) [0x10731d273] 1-17
      17  ??? (diskarbitrationd + 31571) [0x10731db53] 1-17
        17  CFRunLoopRun + 40 (CoreFoundation + 240468) [0x7fff2fb48b54] 1-17
          17  CFRunLoopRunSpecific + 463 (CoreFoundation + 240968) [0x7fff2fb48d48] 1-17
            17  __CFRunLoopRun + 1654 (CoreFoundation + 243217) [0x7fff2fb49611] 1-17
              17  __CFRunLoopServiceMachPort + 337 (CoreFoundation + 245954) [0x7fff2fb4a0c2] 1-17
                17  mach_msg_trap + 10 (libsystem_kernel.dylib + 4474) [0x7fff5cec017a] 1-17
                 *17  ipc_mqueue_receive_continue + 0 (kernel + 1651312) [0xffffff8000393270] 1-17

  Binary Images:
           0x107316000 -        0x10732efff  diskarbitrationd (297.200.5)        <6A57BB14-2FB6-3420-ABDA-429D1991CFE3>  /usr/libexec/diskarbitrationd
        0x7fff2fb0e000 -     0x7fff2ff5bfff  com.apple.CoreFoundation 6.9 (1561) <AC90EE38-93D9-35EF-8359-9FE3A42500D4>  /System/Library/Frameworks/CoreFoundation.framework/Versions/A/CoreFoundation
        0x7fff5cd70000 -     0x7fff5cd9ffff  libdyld.dylib (640.2)               <376E3F3A-6942-3B0E-AD5E-4B97E8255CF5>  /usr/lib/system/libdyld.dylib
        0x7fff5cebf000 -     0x7fff5cee7fff  libsystem_kernel.dylib (4903.231.4) <ABDAABCA-C22A-3960-AA4E-E91A9FF34929>  /usr/lib/system/libsystem_kernel.dylib
   *0xffffff8000200000 - 0xffffff8000bfffff  kernel (4903.231.4)                 <56B30885-F9BA-30E8-AD1C-5D59EC243BA9>  /System/Library/Kernels/kernel

Process:         diskimages-helper [2452]
UUID:            215C14BD-2ABA-36D8-AE6C-6279F4082D96
Path:            /System/Library/PrivateFrameworks/DiskImages.framework/Versions/A/Resources/diskimages-helper
Architecture:    x86_64
Parent:          launchd [1]
Responsible:     backupd [2395]
UID:             0
Footprint:       4080 KB
Start time:      2019-01-29 09:26:56 +0900
End time:        2019-01-29 09:26:58 +0900
Num samples:     17 (1-17)
Note:            1 idle work queue thread omitted

  Thread 0x4f9a             17 samples (1-17)         priority 20 (base 20)
  <thread QoS utility (requested utility), timers tier 3 (coalesced), IO tier 3>
  17  <truncated backtrace> 1-17
    17  mach_msg_trap + 10 (libsystem_kernel.dylib + 4474) [0x7fff5cec017a] 1-17
     *17  ipc_mqueue_receive_continue + 0 (kernel + 1651312) [0xffffff8000393270] 1-17

  Thread 0x4f9e             17 samples (1-17)         priority 20 (base 20)
  <thread QoS utility (requested default), timers tier 3 (coalesced), IO tier 3 and passive>
  17  thread_start + 13 (libsystem_pthread.dylib + 9237) [0x7fff5cf79415] 1-17
    17  _pthread_start + 70 (libsystem_pthread.dylib + 25199) [0x7fff5cf7d26f] 1-17
      17  _pthread_body + 126 (libsystem_pthread.dylib + 13061) [0x7fff5cf7a305] 1-17
        17  __NSThread__start__ + 1218 (Foundation + 73988) [0x7fff31ea5104] 1-17
          17  ??? (diskimages-helper + 52345) [0x106fb1c79] 1-17
            17  ??? (diskimages-helper + 55130) [0x106fb275a] 1-17
              17  DI_kextDriveGetRequest + 43 (DiskImages + 114665) [0x7fff4537cfe9] 1-17
                17  IOConnectCallStructMethod + 38 (IOKit + 34474) [0x7fff325906aa] 1-17
                  17  IOConnectCallMethod + 244 (IOKit + 32413) [0x7fff3258fe9d] 1-17
                    17  io_connect_method + 374 (IOKit + 32827) [0x7fff3259003b] 1-17
                      17  mach_msg_trap + 10 (libsystem_kernel.dylib + 4474) [0x7fff5cec017a] 1-17
                       *17  hndl_mach_scall64 + 22 (kernel + 1426566) [0xffffff800035c486] 1-17
                         *17  mach_call_munger64 + 555 (kernel + 2889483) [0xffffff80004c170b] 1-17
                           *17  mach_msg_overwrite_trap + 910 (kernel + 1717662) [0xffffff80003a359e] 1-17
                             *17  ipc_kmsg_send + 549 (kernel + 1633253) [0xffffff800038ebe5] 1-17
                               *17  ipc_kobject_server + 301 (kernel + 1786557) [0xffffff80003b42bd] 1-17
                                 *17  ??? (kernel + 2706356) [0xffffff8000494bb4] 1-17
                                   *17  is_io_connect_method + 527 (kernel + 8972575) [0xffffff8000a8e91f] 1-17
                                     *17  IOUserClient::externalMethod(unsigned int, IOExternalMethodArguments*, IOExternalMethodDispatch*, OSObject*, void*) + 832 (kernel + 8934912) [0xffffff8000a85600] 1-17
                                       *17  shim_io_connect_method_structureI_structureO + 460 (kernel + 8942556) [0xffffff8000a873dc] 1-17
                                         *17  IOHDIXHDDriveOutKernelUserClient::getRequest64(HDIRequestOOL64 const*, HDIRequestOOL64*) + 257 (IOHDIXController + 11293) [0xffffff7f86529c1d] 1-17
                                           *17  IOHDIXHDDriveOutKernel::getRequest(HDIRequestOOL64*, IOMemoryDescriptor*) + 31 (IOHDIXController + 7179) [0xffffff7f86528c0b] 1-17
                                             *17  ??? (kernel + 1926025) [0xffffff80003d6389] 1-17
                                               *17  thread_block_reason + 175 (kernel + 1876623) [0xffffff80003ca28f] 1-17
                                                 *17  ??? (kernel + 1881552) [0xffffff80003cb5d0] 1-17
                                                   *17  machine_switch_context + 195 (kernel + 2970867) [0xffffff80004d54f3] 1-17

  Binary Images:
           0x106fa5000 -        0x106ff2fff  diskimages-helper (480.230.2)                       <215C14BD-2ABA-36D8-AE6C-6279F4082D96>  /System/Library/PrivateFrameworks/DiskImages.framework/Versions/A/Resources/diskimages-helper
        0x7fff31e93000 -     0x7fff32261fff  com.apple.Foundation 6.9 (1561)                     <27FD022F-F0E3-3053-BADA-DF9BF856CA85>  /System/Library/Frameworks/Foundation.framework/Versions/C/Foundation
        0x7fff32588000 -     0x7fff3261afff  com.apple.framework.IOKit 2.0.2 (1483.230.1)        <AAAF13D1-80E5-3079-98C1-FA3C3FC47B40>  /System/Library/Frameworks/IOKit.framework/Versions/A/IOKit
        0x7fff45361000 -     0x7fff45433fff  com.apple.DiskImagesFramework 480.230.2 (480.230.2) <829D174B-D19D-3302-8C66-0FAD8DF43A6F>  /System/Library/PrivateFrameworks/DiskImages.framework/Versions/A/DiskImages
        0x7fff5cebf000 -     0x7fff5cee7fff  libsystem_kernel.dylib (4903.231.4)                 <ABDAABCA-C22A-3960-AA4E-E91A9FF34929>  /usr/lib/system/libsystem_kernel.dylib
        0x7fff5cf77000 -     0x7fff5cf81fff  libsystem_pthread.dylib (330.230.1)                 <BA382BFC-6A17-3940-B417-D090EF2AF4F4>  /usr/lib/system/libsystem_pthread.dylib
   *0xffffff7f86527000 - 0xffffff7f86532fff  com.apple.driver.DiskImages 493.0.0 (493.0.0)       <81642D4E-F204-3227-8B31-BFC8CD1DDC32>  /System/Library/Extensions/IOHDIXController.kext/Contents/MacOS/IOHDIXController
   *0xffffff8000200000 - 0xffffff8000bfffff  kernel (4903.231.4)                                 <56B30885-F9BA-30E8-AD1C-5D59EC243BA9>  /System/Library/Kernels/kernel

There are many other processes ending up like this: <thread QoS default (requested default), process sudden termination dirty, IO tier 0>

As follows are the processes that had dirty termination (while I don't understand exactly what that means, it doesn't sound good). Listed chronologically:

ACCFinderSync [535]
authd [136]
com.apple.AmbientDisplayAgent [360]
com.apple.appkit.xpc.openAndSavePanelService [53178]
com.apple.ctkpcscd [171]
com.apple.dock.extra [541]
coreaudiod [161]
corespotlightd [744]
CVMServer [317]
diskarbitrationd [67]
distnoted [103]
distnoted [359]
distnoted [397]
distnoted [840]
filecoordinationd [461]
fileproviderd [947]
Finder [525]
imklaunchagent [454]
IMRemoteURLConnectionAgent [433]
IMRemoteURLConnectionAgent [444]
IMRemoteURLConnectionAgent [475]
mds_stores [337]
nsurlsessiond [187]
nsurlsessiond [411]
nsurlstoraged [425]
opendirectoryd [75]
PAH_Extension [455]
pboard [442]
pkd [451]
rapportd [396]
securityd [81]
sharingd [431]
spindump [346]
symptomsd [191]
syslogd [39]
thermald [313]
useractivityd [435]
ViewBridgeAuxiliary [447]
WiFiProxy [544]


I have some good news, which is that since turning off automatic Time Machine backups I have not had this problem! But I still would like to know the cause of it, and if there's a way to still run scheduled Time Machine backups over the network without experiencing severe system problems. I can provide more details upon request.

  • Did this start happening after you updated to the most recent macOS? Try re-updating macOS using the latest Combo Updater. Make a full backup first!
    – IconDaemon
    Commented Jan 7, 2019 at 1:12
  • @IconDaemon What's the difference between the "Combo Updater" and doing a regular update? Because that updater is for updating to 10.14.2, which I am already using. I don't know of any way to revert to a previous version of Mojave. But more importantly, this problem began before I updated, so I believe it is unlikely that changing versions will remedy it. One thing I did just try is resetting the PRAM and SMC... waiting to see if it helps.
    – Mentalist
    Commented Jan 7, 2019 at 1:39
  • Have you tried using sudo killall app\ name to kill them? Not sure if it's different than killing it by it's process id
    – Sam
    Commented Jan 7, 2019 at 2:00
  • You should edit your question to include the information that this problem was occurring before the update to the latest version. How long has it been happening? Since which version of macOS. Another troubleshooting task is to create another user account and see if the problem recurs. If not, the problem lies in your user account.
    – IconDaemon
    Commented Jan 7, 2019 at 2:03
  • @IconDaemon I have edited my question to include that information. I will also try testing on a new user account.
    – Mentalist
    Commented Jan 7, 2019 at 4:58

1 Answer 1


I fixed my issues by clearing up some network shares that couldn't connect. I had three network shares in my user's System Preferences>Users>Login Items. These were all on a server that I couldn't connect to at the time.

For some reason when I opened either Slack or Zoom, they'd attempt to connect to that server.

I can't think why either of those apps were trying to connect there. Zoom especially I've never used its file management or open/save dialogs.

I restarted my network Mac server to restore its filesharing abilities and now my problems have gone away.


More testing. Seems like when Slack opens, it attempts to load all Network Shares the user has in their Startup Items. (Another person noticed this behaviour in this Reddit thread.)

  • 1
    Posting a comment as an answer will usually get you downvoted on Stack Exchange. Unfortunately there is no other way to communicate a comment when you have no rep, so I can relate to your frustration. In my case the problem seemed to be fundamentally linked to 2 things: Time Machine backup scheduling, and a Windows-based company LAN. I never figured out why it happens, but in my case I turned off TM auto-backups and now do them manually once a day. Since that hasn't worked for you, I'm afraid I don't have any further advice. But I would be curious to hear what AppleCare would have to say.
    – Mentalist
    Commented Sep 17, 2019 at 23:31
  • 1
    I did some more debugging and it seems to be related to network drives. For some reason when I opened either Slack or Zoom, they'd attempt to connect to another Mac on my network that I host most of my network shares on. This Mac was unavailable. I can't think why either of those apps were trying to connect there. Zoom especially I've never used its file management or open/save dialogs. Maybe they were both looking in my recently used folders? I restarted my network Mac and now my problems have gone away. Hell if I know how that could have worked.
    – MrTemple
    Commented Sep 18, 2019 at 0:00
  • 1
    Thanks for sharing your solution! (And congrats on your first answer) About Login Items... I had two LAN chat apps that are used within the company set as Login Items. If they were tying to connect before a network connection was established by the OS that could've been part of the problem. I decided to remove those from the Login Items list and instead add (1)an alias that points to a network folder, and (2)an app I made using Automator that runs an AppleScript that will wait a number of seconds and then launch the 2 apps. I'll report results.
    – Mentalist
    Commented Sep 18, 2019 at 6:45
  • My Login Item network shares were simple aliases to the network shares. I can't imagine why they'd try to be reconnected when some apps open (or how apple would allow that).
    – MrTemple
    Commented Sep 19, 2019 at 16:36
  • I regret to report that my latest effort has not solved the problem. I am reverting to my previous approach of disabling automatic Time Machine backups.
    – Mentalist
    Commented Sep 26, 2019 at 1:31

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .