I've purchased several ebooks within the last few years, some of them for reference. I tried to open one recently and the content will no longer authenticate. I can't get the ebooks to work in either Adobe Reader (older and most recent versions) or Digital Editions. I get this message: "This document cannot be opened on this machine. Please contact the site where you obtained the document to download another copy." I believe that I've only had my ebooks on one computer. How does the verification process work? Does it go back to the server from the vendor who sold you the book? I bought most of these ebooks at Amazon, but they are no longer supporting Adobe books. When I checked my Amazon account to try to re-download my books, there's no access to my digital library. I contacted them and they are of no help.
Is there anyway to access the ebook copies or are they permanently lost?