I tried to copy to the same hard drive in a different folder but failed. I tried a few different actions:
1. rebuild aperture library
2. disk utility to check integrity
All of these shows no errors at all.
My timemachine is working fine, therefore I recover the library to a different folder but some of the photos have errors.
How can we save the opened library under Aperture in a different name of different folder, just like MS Word saved the file in a different name?
The Aperture Library is a database wrapped in a Finder package file. Although it appears to the user as a single document file (like a Word doc), it is quite different. You can't "save as" and thus create a duplicate. You must duplicate the Library file using a file manager (e.g.: Finder), at which point it will be automatically given a unique name (which you can change, again using a file manager).
Have you repaired Aperture permissions (directions are on Apple's Aperture trouble-shooting page), as well as your system permissions (via Disk Utility)? If not, I would do so.
The indications are (as mentioned in this thread) that you have a corrupt file (or files) in your Library. Afaik, there is nothing to do except search them out manually. Check the Apple Aperture Discussion forum for suggestions on how to do this (look for posts by LeonieDF).