Camera Connected - Aperture Doesn't Open

Are you connecting your camera directly or using a card reader? Aperture may not be able to recognize the camera when directly connected (low battery, broken cable). I'd try to use a card reader.

If your card reader is not recognized, try a different card or reformat your card in the camera (after saving the images on the card)-

I have trashed Aperture preferences in Go > Library > Preferences. This didn't solve the problem.

Did you give Aperture and Image Capture time to save the Preferences? Quit Aperture, quit Image Capture? Logged off and on? Remove Preferences only after log off and log on again, otherwise Aperture may simply restore them from the Cache.

There may also be a problem with the Image Capture preferences. If all fails, try to remove those.

Regards

Léonie

The basic problem is that Aperture's preference re opening when a camera is connected reverts to "no application"

upon re-launch.

That indicates that Aperture's preferences file is corrupted. And that is the reason that I asked, how you removed the preferences. If you do not ensure that Aperture really quits by logging off and on again, before you delete the file, it might simply be restored from the saved process state (Mt. Lion's fast resume and automatic termination feature) and the deleting of the preferences file will not help.

Another reason that the preferences cannot be written may be that your user library has a permissions problem. Is the "Preferences" folder writable?

Not sure if this will help, but in Mountain Lion - Apple added a folder in the user library called 'Containers' (so the address is '~/Library/Containers').

If I understand it, this has to do with the newest implementation of sandboxing apps. I believe some of the preferences are redundantly stored in this folder for the various apps that sandbox. Aperture is definitely one of them.

You might try moving the Aperture folder found in Containers to the desktop and see if that sorts it.

Note - I have deleted this folder without consequence other than resetting preferences a couple times (OS X 10.8.2 / AP 3.4.2). 😉

I noticed that the preference setting was not "lost" when I closed and relaunched Aperture.

That is very typical for MacOS X since Lion. When you are quitting an application it will not necessarily terminate. MacOS X may keep its processes alive, just in case you will want to relaunch it again soon. Only log-off or reboot will ensure that the processes terminate and you can safely remove preferences and settings.

So, if you notice, that the settings are lost, after rebooting, that indicates that Aperture could not save the setting on termination.

There are three Aperture items in the folder, namely:

com.apple.Aperture.plst

com.apple.Aperture.plst.lockfile

com.apple.Aperture.plst.y7t8cVD

Should all three be deleted or the first one only?

After rebooting only the first two should be there. If the third is left over, it may be corrupted. I'd remove all three of them.

The folder Corky pointed out (~/Library/Containers/com.apple/Aperture) is a cache where Aperture shares the data with other processes while it is running. t should be recreated each time aperture launches.