I have bought and downloaded an e book for ADE on my pc and can read it there. I want to read it on my Samsung galaxy tab. to do this I understand I have to authorise my computer and then use the same login details to authorise my tablet. I already have an Adobe account so I input my email address and password which works fine for eg Creative Cloud but not for ADE. I get the error message "you can only authorise this computer with an adobe id that hasn't been previously used to authorise any other computer or mobile device". My PC is running Windows 10 pro.
I see someone else had a similar problem a while back but no resolution advice was posted.
I tried Adobe Technical Support on chat but they don't answer technical questions apparently hence my cry for help from you guys.