As per title. I installed Mavericks today and all was fine for about 6 or 7 hours. All of a sudden several apps won't launch. They either 'bounce' once or fail to open, or don't bounce at all. Here's a list of apps that it happens on (NOTE - only Apple apps seem to be affected): App Store iCal Pages Numbers Keynote iMovie* Terminal iBooks QuickTime & more. For contrast, apps that do work: Mail iTunes Logic X iPhoto System Prefs Finder & more. Here's what I've done so far to no avail: Repaired disk permissions Deleted plist files in ~/Library/Preferences Booted in safe mode Created a new user and checked in that user. If anyone can shed any light I'd be so happy. I'm pulling my hair out here! Cheers.