The book in this case is not returnable (whover you borrowed it from did not turn on the extra bit to make it so). Is wherever you are downloading these files from stating that they should be returnable?
I wouldn't know, Jim. I have been using EBSCOhost for my book loans. Are you (or is anybody else) familiar with this eBook resource?
Let's look at the ebook's entry in the library to see if it's shown as
borrowed or not.
The ebook's entry in the Library should show a small banner that says it's
a borrowed ebook. If you click on the small arrow next to the ebook's
name, the drop-down menu that appears should contain an entry for 'Return'
if the ebook is recognized as a borrowed ebook.
If the ebook doesn't show any indication that it's borrowed from the
library, contact the library's technical support function and tell them
what you're seeing and what's happening. I think something on their end is
messed up: ADE just puts ebooks in the library based on the coding embedded
in the ebook's file.