Mac OS X Dock Not Working

What follows is my real-time trouble-shooting of a Mac OS X problem I had two mornings ago. I was unable to find a solution online, but I did manage to get things back to normal. I’m posting this so that it might help someone else with a similar problem.

The Symptoms

My OS X Dock isn’t there. It just vanished. Also:

  • Command-tab doesn’t work
  • My desktop is just black
  • Files and folder appear on the desktop, but there’s no wallpaper
  • Right-clicking on the desktop doesn’t do anything
  • Mission Control/Exposé doesn’t work either

Trying to kill/restart the Dock process from the terminal doesn’t work:

$ killall Dock
No matching processes belonging to you were found

Activity Monitor shows the ReportCrash process running and using ~10-11% CPU. It respawns after I kill it.

Reboot doesn’t help. Everything is fine if I log in as another user.

System seems fine otherwise. If it wasn’t for LaunchBar, I wouldn’t be able to do much of anything on this MacBook.1

The Origin

Seems that this issue started when I added a new folder of images (from Solid Color Backgrounds2) to the Desktop & Screen Saver preference pane. The folder was full of 1000+ tiny 1×1px PNGs. Or maybe it was the folder of 1000+ 640×480px JPEGs. The folder was added to the preference pane just fine, but trying to use one of those 1000+ images as the desktop wallpaper didn’t work. That seems to be what killed the Dock and made the desktop non-functional.

The Fix?

I deleted the folder of images I had added to the preference pane. I removed both the reference to the folder in the Desktop & Screen Saver preference pane and I deleted the folder itself from Finder. Shortly after that, the desktop appeared and the Dock came back.

  1. I forgot to check if Spotlight worked or not. 
  2. But I don’t want to blame that site for this problem. I likely made some changes to the images after I downloaded them. And they worked fine a year or two ago on this same computer.