Locked Pages on iCloud

I can't open my locked pages on iCloud.

I wanted to share a document on iCloud with a friend of mine. We decided to password protect it, and now I can't open it anymore.

The preview of it works, but we can't do anything else about it...

The password is correct, it seems, as I can see the document preview.

But whenever I type the password, "pages cannot be opened" appears.

I don't think there's a problem with the pages/iCloud itself, because I can open other pages.

What do you think I should do? THis is a very important document, adn would rather not lose it...

Thank you.