The savest way to try to fix this would be to reinstall the system, but a quick and dirty way that helped in some cases is to restore a cache file, see
and also this thread: Re: Import video to Aperture library on Mountain Lion
I've had the same problem after an Apple Programmed HD change and restore with a TM backup. I have replaced the com.apple.xpchelper.cache file from my MacBook Pro and it works. Only the preview are all corrupted and I don't know how to fix this. BTW, following your advise, I would like to reinstall the OS, but if I use my original CD I miss all the OS update and it will took a whole life for me. Have you any solution to do this?
I am at the Airport changing planes right now and have only a poor internet connection.
What is your MacOS X version? If you are using Lion or Mt. Lion, try to reinstall by booting into the Recovery HD: http://support.apple.com/kb/HT4718
And if you are using an earlier System, look for a Combo Installer on the Apple Support Page:
Have you tried to select your Videos and to update the previews?
The one step I also did that I didn't mention before.
Once I reinstalled Mountain Lion which gave me the com.apple.xpchelper.cache file back.
I went into Aperture,
I checked that the movies would play.
Like Massimiliano1 the previews were still screwed up so I selected the movies option-right-clicked the movies and choose Generate Preview.
The Option button changes the "update preview" to "Generate Preview" in the menu
All is well.
On wither or not to reinstall. If the above worked, you are ok, but I would still recommend reinstalling the OS so you get your recovery partition back. Never know when you are going to need it.
I'm downloading the OSXML 10.8.2 combo installer to reinstall OS. I have update the movie preview like written by USKiwi, but noe I miss some pictures. Some preview are missing some others are black. If I try to generate preview nothing happen and if I try to reconnect the picture to original Aperture says that the original is missing or off line, but this is not true. I have repaired the librrary with the command-option feature, but nothing changed.
I'm really upset and I have a strong desire to move to Windows again: this is hardly acceptable.
How can I try now?
and if I try to reconnect the picture to original Aperture says that the original is missing or off line, but this is not true.
Massimiliano, are your originals referenced or managed?
If they are referenced, outside the Aperture Library, and you know where they are, you should be able to reconnect them by selecting them and using "File > Locate referenced Files". Wheer do you see the offline message?
And below the corrupted preview you see the path where Aperture is looking for the original file.
Are your originals at the location Macintosh HD/Users/imac_27/Pictures/foto di famiglia .... ?
If yes, have you tried to select this path in the file choser in the lower part of the reconnect window by clicking on "Macintosh HD"? if you can find the image there, the reconnect buttons should become active.
I've connected an old HD on which I have stored my odl pictures and relocated them from the external HD. Now I'm generating new preview.
Now my question is: are this files only in the external HD or have been imported in the Aperture library again? And if not there is a way to find out which files are not in the Aperture library and import the as managed files?
I've connected an old HD on which I have stored my odl pictures and relocated them from the external HD.
They will be, where you relocated them to. What destination did you select?
If you want your images to be managed, don't relocate, but select them and consolidate. Consolidating will move them into the Aperture library.
To find out, which images need consolidating, define smart albums:
File > New > Smart Album
Then add a rule: FIlestatus is Referenced (or offline or missing, if still images are missing)
Set the source of the album to "Library"
This album will contain all your referenced images, that need consolidating.