DRM Issues

I have nearly 300 epub and pdf books previously controlled under Adobe Digital Editions (which is still downloaded to my laptop under Windows 10) and running on my Sony E-Reader. I backed up the books to my laptop where they now reside in my Digital Editions directory. My e-reader was stolen from my hotel room in Ethiopia. As Sony no longer support an e-reader I purchased a Kobo Aura One e-reader and using Calibre downloaded all my books to the Kobo.

I now find that when accessing the e-pub or pdf files that do not have a Kobo e-pub tag, I encounter DRM. Fair enough. However when processing the authorisation procedure I am advised that my authorisation ID (my email address) that I was told to use by Adobe Customer Care person does not work. The system advises me that the book I am selecting does not relate to my authorisation ID. I have selected numerous books on the Kobo and the same issue is encountered. I have 285 books, which were imported to my Kobo and all of them have the DRM issue.

Through Digital Editions with my Kobo interfaced via USB, I have de-authorised and re-authorised my Kobo - to no avail. Has anyone had the same experience and is able to share the solution to this issue?