See if any of these "similar" previous discussions will help
Missing Library Files http://forums.adobe.com/thread/398764
Plus CS6 - http://forums.adobe.com/thread/1006810
Deactivate PP then close it down. Reboot the system, then start PP and reactivate.
SOLVED ! Update Premiere CS6 (help >> Updates...) and all presets go back to normal , it works for trial too !! hope it helps, it works for me