I've same error: E_LIC_ALREADY_FULLFILLED_BY_ANOTHER_USER.
I've discovered that ID for ADE was different in my first PC where I downloaded two purchases e-books than the second and my personal PC.
Unfortunately I can't remove totally second installation of ADE, because the second PC always remember the second (and wrong) ID authorization.
I have desinstalled ADE several times, I have gone to Adobe.com, coming into with the appropriate ID but this is the same,
and Adobe Support can't help to me until this time.
Please if somebody can help us.