I too, have this problem.
I tried returning a book for the first time, and it appeared to work.
I tried returning a second book, but I think my link died, because ADE 2.0 crashed. Throughly. Report sent to microsoft.
Thereafter, when I tried returning the book, it gave me:
This is not a helpful message.
Other, much older (antique!) posts said to download the older version of the software.
Someone had to pay $68 to find out that Adobe doesn't know what's wrong, and no longer supports this product.
My library only allows me to have 10 e-books checked out at a time. If I can't return the books, I have to wait WEEKS before I can borrow new ones.
I have been trying desperately to find an alternative software that can read ePUB format. My link is way too flaky to be able to read online: I have to be able to download books.
Right now, I'm back to good old paper books (which never crash, can be returned when I'm done with them, and the only limit is how many I can carry.)
Please let me know where I can find non-buggy alternatives.
Quite often the older v1.7.2 does cure issues.
Not sure if it is officially still supported, but generally works.
I assume 2.0.1 is supported, but sadly doesn't work in many cases, and the level of support is pretty much equivalent to 'not supported'.
There are lots of bugs in ADE2.0 (and 2.0.1). 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
Some people have found ADE trying to upgrade automatically.
It appears (not 100% sure) that if you install ADE2.0 as a new install (not as an upgrade) that your 1.7.2 will continue to run.
Probably best to say no if 2.0.x installation asks if you want to migrate your library.