I've been working on a book manuscript in PAGES for several months on my Macbook (new, running Yosemite). Just updated my desktop to Yosemite -- no apparent problems -- but am not able to open manuscript files on the desk machine. I get a "can't open" with the message "the required index.xml file is missing".
Also, I'm still seeing the earlier PAGES icon in the dock, although I know I've 5.5.3
Any help appreciated!