Hi,
What is the version of mac osx that you are using?
Please follow this step.
Click on GO- Go to folder- ~/library-application support and rename the adobe folder to old adobe
now go back to ~/library and then go to preferences and rename the adobe folder
go to documents and rename the adobe folder
By doing this you would loose your synced settings, customized keyboard shortcuts and customized effects.
Thank You
Arjun