Currently Being ModeratedSep 16, 2012 12:29 AM (in response to léonie)
Thanks for superfast feedback
but in Library/Application Support/ProApps there is just a folder Internal Plugins.
In the also mentioned location /tmp I also can not find the File "ProAppsSystemID"
Currently Being ModeratedSep 16, 2012 12:53 AM (in response to Bikul)
what happens, if you log in from a different User account. You may try to create a new account with admin priveleges just for testing (from the "System Preferences > Users & Groups" preferences pane).
Quit Aperture in your account and log in as the new user, then register Aperture there. Does it remember the serial number?
if that is the case, you may have a problem with your caches or your user preferences.
Currently Being ModeratedSep 16, 2012 7:58 AM (in response to Bikul)
Have you tried to repair the permissions on your system volume? Maybe you have a permissions problem and Aperture cannot write to the /Library/Applications Support folder.
To repair the Permissions you can use Disk Utility: Select your system volume in the left panel and open the "First Aid" tab. Then press "repair Permissions":