I downloaded a book and used Adobe Digital Editions to open it. I did not create an adobe ID but authorized my computer without one. Okay cool, I could still read my copy of the book on this computer. I then contacted the customer support chat and asked them if I could authorize my computer with an ID I had created afterwards on my mobile device (So that I could share that book I bought on other devices). They told me to un authorize my computer and then authorize it again with my new ID. So I did that. But low and behold now I'm not able to read my book because "The Vendor account you entered is not associated with the item you are trying to open." So Now I've got absolutely no way of reading this product that I have purchased, which, by the way, wasn't cheap at all. Then they directed me here to another thread, and I tried the "Solution" posted there saying I should authorize my computer with the credentials used at the time of the book download, but since I authorized my computer without an ID I very well can't "use the credentials that were used during book download". So if anyone has a solution that would actually allow me to read my book, I would be very, very glad to hear it.
You get the error when the eBook are linked with a other Adobe ID or empty authoirze. Often its happens when you open/download a eBook before you authorize Digital Edition. Then authorize and can the eBook no longer read. In this case can you only ask his reseller for a new download which can right linked with our ID.