Ereader not authorized to open this book

Hello!

I haven't used my Kobo in a few years to read library books. Today, I decided to try using it again. I had to reset my password to regain access to my Adobe Digital Editions (ADE) account. I am able to download books from  OverDrive to ADE. When I connected my ereader to my computer, I was able to drag the library book from recently added to my ereader. However, when I disconnected from my computer, and tried to open the book on my Kobo, the error message told me I had to reauthorize my eReader. I have tried deauthorizing this e-reader (even though ADE tells me it is authorized) and reauthorizing it. I got the folowing message: "This book is protected by Adobe Digital Rights Management (DRM). Because you previously deauthorized your eReader you need to re-import the book using Adobe Digital Editions". I have tried doing this multiple times, deleting the old copies of the book from ADE and my Kobo and redownloading from the libary. I even signed out a new book from the library to try and keep getting the same message. I saw on one thread that if you de-athorize your computer and your kobo it will work. So I de-authorized (and reauthorized) my computer and my kobo once again. I keep getting the same error message and I am getting frustrated. I wish ADE was more user friendly. Please help!