I just ran a system update on Lion and after the reboot I got issues with Mission Control.


  1. When I trigger Mission Control, it only shows windows on current space and doesn't provide a way to add or switch between spaces. The whole top bar is missing.
  2. When I trigger Launchpad, it shows on a background that has nothing to do with the desktop background image, as if the underlying image was black.
  3. Changing background image in Preferences doesn't take effect until a restart.

This is very frustrating and seems like a bug. How do I fix this?

2 Answers 2


Seems like I'm not the first one to hit into this issue, and it is related to Dock process working incorrectly. The easiest way to fix this is to type

killall Dock

into the Terminal, which will effectively relaunch Dock process (and hopefully fix the problem).

If this doesn't work, reportedly trashing Dock preferences and attempting several restarts may help.


If literally just installed Lion in the past 30 minutes then you need to give the system time to "settle." I noticed a lot of the same issues immediately after upgrading from Snow Leopard and they all resolved themselves with a bit of time.

  • I installed an update on top of “clean” Lion installation in the first 30 minutes of running it so I figure you're right. Works fine now, anyway.
    – Dan
    Sep 23, 2011 at 21:35
  • 1
    No, this is just a bug that happens sometimes. Still happens to me, a year after installation. And it happened sometimes on my previous Lion installation too. killall Dock fixes it.
    – callum
    Sep 27, 2012 at 11:34
  • This is happening on my Mountain Lion system that was just opened from the factory box 5 days ago. The killall trick works though! Jan 12, 2013 at 23:10

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