You get the error that fulfilled by another User when the eBook are linked with a other Adobe ID.
Often its happens when you open/download a eBook before you authorize Digital Edition. Then
authorize and can the eBook no longer read.
ADE was already authorized, and it wasnt fulfilled by another use - it was direct from the site...any other suggestions?
If you not have a empty authoirze or a other adobe ID its a error with the file itself. Have you ask the reseller for the eBook to check the file?