How to remove corrupted preferences:

Quit the application that is causing the problems.

Choose Optimize > Remove Corrupted Preferences.
The applications on your Mac store settings and similar information in preferences files. Occasionally such a preference file may get corrupted, causing problems with the application.
If you experience problems starting or running an application, see if the preferences file has become corrupted.
Quit the application that is causing the problems.
Choose Optimize > Remove Corrupted Preferences.