Check ctrl-I that the book has appropriate permission (Viewing: on any device).
There are bugs in ADE2.0 relating to library books and certain devices (and lots of other bugs as well).
You could have hit one of these.
There are lots of bugs in ADE2.0. Try replacing ADE2.0 with the older but more reliable v1.7.2.
(You can have them both installed at once if you like.)
Version 1.7.2, it is a little difficult to find, available on Adobe site for Windows and for Mac.
The forum software is sometimes corrupting the link above. There shouldn't be a blank in 'editio ns.html'. The following redirects to the same page: http://tinyurl.com/diged172