IPhoto cannot open

Question

On our laptop, we are running 10.6.8 and whenever I try to open iPhoto, I get the message, "You can't open your current photo library. You have made changes to your photo library using a newer version of iPhoto."
I believe this happened when we backed up our laptop photos and opened them on our desktop to make sure the backup worked.
How can I get iPhoto to open again so that we can upload photos and edit them again? Thanks in advance.

Answer 1

Download iPhoto Library Manager and use its rebuild function. (In early versions of Library Manager it's the File -> Rebuild command. In later versions it's under the Library menu.)
This will create an entirely new library. It will then copy (or try to) your photos and all the associated metadata and versions to this new Library, and arrange it as close as it can to what you had in the damaged Library. It does this based on information it finds in the iPhoto sharing mechanism - but that means that things not shared won't be there, so no slideshows, books or calendars, for instance - but it should get all your events, albums and keywords, faces and places back.
Because this process creates an entirely new library and leaves your old one untouched, it is non-destructive, and if you're not happy with the results you can simply return to your old one.