Q Recently, when I start my Mac up, the Dock crashes a few times before it settles down. Activity Monitor says that it is then stealing 100% CPU usage, and my logs reveal around 20 crashes in just 30 seconds, with reports relating to the setting up of an icon. How can I fix this?
A If you don’t have many icons in your Dock, an easy solution might be to take a screenshot so that you can remember what is where, remove all the icons, restart your Mac, and replace the Dock icons from their original applications.
If the crashes persist when you have started up with an empty Dock, then you should look whether you are using a Dock enhancer or customisation, such as an extra separator icon added with a tool such as Secrets. These can become unstable if you are not careful.
You might also fare better if, after the restart, you trash the file ~/Library/Preferences/com.apple.dock.plist in case that has become corrupt.
If you have a lot of icons and this seems too laborious, you can Command-click their icons and choose the Show in Finder item in the Options menu item to highlight the parent item in the Finder, so you can drag the existing icon out and put a fresh replacement in immediately. If all else fails, try restarting with an empty Dock and the Shift key held down, for Safe Mode.
Updated from the original, which was first published in MacUser volume 27 issue 18, 2011.