Lately when I open iCal it just pretends to open, the icon bounces up and down for a while, when I click command-tab, it shows up as an open app, but isn't actually open.
Make sure you Quit iCal
In Finder > Go > (hold down Option key) Library > Preferences > find the file called "com.apple.iCal.plist" and drag it to your Desktop.
If the issue is resolved you can move "com.apple.iCal.plist" to trash.
Thank you, Axeman!
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