Renaming the volume or folder in which the Aperture library resides
Aperture will continue to look in the old location until you tell it differently. To do this:


Quit Aperture before changing the volume/folder names.
Make your changes in Finder.
Reopen Aperture and go to Aperture > Preferences.
Click General, if necessary.
Under the Library Location option, click Choose.
Locate your library and click Select.
Quit Aperture and restart it.