Can anyone help: License server communication Problem

Im trying to download some ebooks, however i keep getting an error message that reads error getting licensee. License Server Communication Problem: E_LIC_ALREADY_FULFILLED_BY_ANOTHER_USER, i think they may have been downloaded before digital editions was authorized, but now I can't access them at all.

Can anyone help solve this issue, the ebook vendor says it isnt there problem but an Adobe one