Multiple device sign in

[#1]

I am getting the following error message when trying to sign in/authorise a second device with my Adobe ID to access purchased texts with Adobe Digital Editions 4.5.

"You can only authorise this computer with an Adobe ID that hasn't been previously used to authorise any other computer or mobile devices. Please Try Again"

Not sure if it's an account issue or what?

Any help would be great!

Thanks

[#2]

I am getting the following error message when trying to sign in/authorise a second device with my Adobe ID to access purchased texts with Adobe Digital Editions 4.5.

"You can only authorise this computer with an Adobe ID that hasn't been previously used to authorise any other computer or mobile devices. Please Try Again"

Not sure if it's an account issue or what?

Any help would be great!

Thanks