How to repair documents that display the “The document xxx.pages could not be opened” error when opened in Pages? I recently did a clean Mountain Lion install, after which I restored some important Pages documents from a backup HD.

Now, when I try to open these documents in Pages, I get the following error:



Someone in this old thread on the Apple support forum suggested to use Disk Utility to repair disk permissions, as well as the disk itself, but that doesn’t seem to help.

The weird thing is I can still open these documents using my girlfriend’s laptop just fine. I tried opening the file on her Mac, saving it, then transferring it back to my laptop, but no luck — it still shows the error message.

Any other ideas as to how these documents can be repaired?
I ended up buying and installing Pages from the App Store; I was using an old iWork copy before. Sucks that I bought the same product twice now, but at least I could open my files after that.