I am getting exactly the same problem on a PRS-650 when trying to open a particular book ("Bring up the Bodies") purchased from Kobo. All I get on the screen is a message saying "Page Error". And yet I can open and read the book using the Reader Library software on my laptop. I've never had anything like this before and wonder if it could be tied up in some way with the DRM system - but don't seem to be getting much help from Kobo.  As jucouti46 asks - any ideas?

This could be a corrupt down load, if this is the only one you have trouble with - but if you can read it on PC, that's unlikely.

Have you tried deleting the book from the reader, and then re-installing it ? That's worked for me.

Next thing to try would be to delete book, do a soft re-set, then re-install - see what happens.

If neither work, contact the provider and ask if they've had any problems with that download for epub.

Finally,  there's Sony Support.