Issues with ADE transferring books to Kobo Glo

I'm not sure if this is a Kobo Glo issue or an Adobe Digital Edition (I have Version 4.5) issue but I downloaded Overdrive in July last year. I've had no issues with it until this morning when I downloaded some books and tried to put them on my Kobo via ADE. They went onto my device but when I tried to open them it said something like I don't have permission to read them.

I deleted the books off my Kobo, returned them to Overdrive in ADE, and deleted them off my downloads on the computer.  I re-borrowed them from Overdrive but now every time I go into ADE, there are books I downloaded and returned months ago and nothing will go over to my Kobo any more. I tried doing a factory reset on my Kobo, downloaded an earlier version of ADE, erased Authorization and re-Authorized, uninstalled and re-installed the version I already have, no avail.

I can't find any information about other people having the same problem with the old books continually appearing every time I go into ADE and I don't know why nothing will go over to my Kobo - I always do it the exact same way!

Hopefully someone can help!