Aperture 3 "hangs" on startup
I recently imported some old photographs into my Aperture library from an external disk drive, used to backup the Windows PC where the files were originally managed. When I open Aperture now, I get the spinning icon in the lower left of the screen and Aperture is unresponsive. I can see all of the project thumbnails but cant open any of them.
I have tried running the Apeeture first aid utilities to no avail.
I'm running Aperture on an iMac 11,3 and have the current version of Aperture.
Has anyone been able to resolve a similar problem?
Aperture 3, iOS 5.1, iMac 11,3 20 Gb memory