As stated above VDCAssistant seems to be causing perpetual crash reports to the point that the ReportCrash system process will use 50-100% of cpu.

Application Specific Information: Client is attempting to access a display by index (1) instead of display ID. abort() called

These crash reports also seem to disappear and reappear. (i.e. the number of crash reports in Console.app never grows but are constantly being generated). The process cannot be force quit.

I have no idea whats causing this as I don't use iSight camera and nothing else is connected to laptop (macbook pro 4,1 osx10.9.2)

Logging out does not cure it, but a restart will.

  • What OSX version do you have? I started having the same problem right after update to 10.9.2
    – Hubert OG
    Mar 19, 2014 at 8:40
  • 10.9.2. Never noticed it before that but that just may be an oversight on my part.
    – pat
    Mar 25, 2014 at 14:21

7 Answers 7


Apple has changed something that interferes with some applications/drivers using the webcam, mirroring the screen (Airplay and Airplay-like) and providing USB graphic cards.

Uninstalling those (make sure to use Google to find what kernel extension they installed), make sure the system rebuilds the kext cache by running

sudo touch /System/Library/Extensions

and restarting solves the problem for most people posting to that list.

List of applications I found that might cause the problem, mostly out of a lengthy thread in the Apple support forum:

  • Air Display
  • AirParrot
  • AirServer
  • DisplayLink Driver
  • iDisplay
  • Parallels
  • Splashtop virtual display driver
  • ScreenRecycler
  • VMWare

Not all of this must be affected, and some are actually debated in the thread (like Parallels and VMWare). They might just do the touch mentioned above which some users probably didn't do.

Sadly this all didn't help me, so I decided to give up the camera until Apple fixed this and disabled the VDCAssistant (must be repeated after each boot, when the problem still occurs, and whenever something wanted to access the webcam). Has the advantage over deleting/renaming that you don't have to remind yourself undoing that if it finally is fixed; but you realize very well if the problem still persists after a reboot...

sudo launchctl unload -w /System/Library/LaunchDaemons/com.apple.cmio.VDCAssistant.plist
  • thank you very much. At least I now know that there is an apple controlled light at the end of the tunnel and a few possible fixes if I feel the camera is needed again.
    – pat
    Mar 27, 2014 at 23:02
  • That plist unload does indeed fix the problem. For me the problem occurs inside a Parallels VM running Mountain Lion, triggered by running Google Chrome. Jan 4, 2016 at 21:54

Temporary workaround found

VDCAssistant kept restarting and crashing, spawning a ReportCrash process that was eating up a lot of CPU. iSight is not working. In order to keep my early 2009 iMac working (2009)

cd /System/Library/Frameworks/CoreMediaIO.framework/Versions/A/Resources/VDC.plugin/Contents/Resources/

sudo mv VDCAssistant VDCAssistant.stopme

This seems to have stopped the crash/report/respawn cycle. I don't know if it has any other effects, but my CPU load is back to normal.


It seems to be potentially caused by third party apps used for display mirroring or streaming. In my case it was caused by AirDisplay and removing that program solved it. Try to boot into safe mode and when the problem disappears in safe mode it is almost certainly caused by third party software.

  • Exactly how did you remove "AirDisplay"? Nov 22, 2015 at 19:25

As explained above, disabling VDCAssistant seems to resolve this issue. However, even after disabling this, there are some other errors that can appear e.g. this error logged in the console several times per second:

WindowServer[432]: _CGXGLDisplayContextForDisplayDevice: No matching context for device (0x7f9c42d034c0) - disabling OpenGL

(mentioned here)

I haven't found a workaround for this aside from rebooting and/or disabling the DisplayLink adapter (the cause of the issue for me). Hopefully this is pending a patch from Apple.


Opening Windows 7 through Parallels seems to be the trigger that sets the crash cascade in motion. Thrashing VDCAssistant seems to have cured it in the short term. Hopefully it does not lead to other issues down the road.

  • I have this same issues, but I'm not using Parallels, though I did have it installed years ago. Any new information on this?
    – iynque
    Mar 6, 2014 at 21:21
  • Unfortunately this solves one problem but creates others. For me its not an issue as i don't use the camera but trashing VDCAssistant disables it (which could be good if you are super paranoid and don't believe gaffer tape is opaque enough!)
    – pat
    Mar 6, 2014 at 21:38

Google Chrome

enter image description here

Removing the Google Chrome web browser solved the problem for me.

I was running Mountain Lion in a Parallels 11 virtual machine, and had a crash log generated repeatedly as described in the Question, with names such as VDCAssistant_2015-11-22-120350_localhost.crash. The repeated crashes started only after launching Google Chrome. Quitting Chrome does not stop the crash log creation, logs continue to appear every few seconds until a reboot.

I disabled access to the camera in the Chrome preferences. Did not help.

I deleted:

  • Google Chrome app from Applications folder.
  • ~/Library/Google/
  • ~/Library/Application Support/Google/

I downloaded and re-installed Google Chrome app again. Problem does re-appear.

Gave up on Chrome, and removed the app again. Firefox is now my secondary browser instead of Chrome.

Alternative - Delete .plist

An alternative is described in the Answer by Jens Erat where you use the Terminal to delete a plist. Deleting the plist does indeed immediately stop the problem. However, you must delete the plist every time you reboot the Mac (or Mac VM in my case).


I know this is way too late, but i simply disabled camera sharing from Parallels.

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