Had bought an eBook in early 2019 and it didn't have any problem opening it on Adobe Digital Editions (ADE). However, I recently had to format my PC and redownload Adobe Digital Editions.
Even though I had authorised the second ADE download with the same Adobe ID with which I authorised the previous download (with which I opened the eBook successfully), I am still getting the same error (see image). I redownloaded the eBook from the retailer's website (I can redownload it only a five times, I think) but I am still having the same problem.
I requested the retailer for a new download point i.e. a copy of the eBook with a fresh, blank license; but they refused as the book was no longer available on their website. They also unfortunately refused a refund because the purchase was made long back. My only option is to get the Adobe Digital Editions to work somehow. 😞
Please cross check if you are Authorize with same Adobe Id/Vendor Id in ADE by which you have purchased the book. If the account is the same, then the only option would be to reach out to your e-book provider and ask to issue a new ACSM token.