Aperture updated to 3.4.5 is now crashing on startup.

Question

I updated form 3.4.4. I was able to open the program, import some photos from my camera, post online and quit. Now when opening Aperture it immediately hangs and freezes. My activity monitor shows CPU usage at 247% and 20 threads being utilized and that the process is non responsize.
Any suggestion as to how to fix this?
This is on my 27" iMac running OSX 10.8.4

Answer 1

Now when opening Aperture it immediately hangs and freezes. My activity monitor shows CPU usage at 247% and 20 threads being utilized and that the process is non responsize.
That looks like a freeze caused by Aperture not being able to process the imported image files, when trying to render previews or the library may need repairing.
Can you launch Aperture, if you defer the generation of previews? To do that, hold down the shift-key ⇧ firmly, while you launch Aperture by double clicking the Aperture icon.
If Aperture launches without freeze, then one of your most recently imported images or videos cannot be processed. Turn on the Activity viewer (Fom the main menu bar: Windows > Show Activity) and then try to start the rendering of previews manually. The Activity viewer will show you, which images are currently being processed. Remember the filename and remove that file from the Paerture library.
If deferring Preview generation does not help, try, if Aperure is working well from a different user account: (see: Isolating an issue by using another user account) and post back with your results.
Regards
Léonie