license server communication problem: E_ADEPT_DOCUMENT_TYPE_UNKNOWN

license server communication problem: E_ADEPT_DOCUMENT_TYPE_UNKNOWN

Trying to download and open a an ebook. However when downloading the content i get the following error message:

error getting license. license server communication problem: E_ADEPT_DOCUMENT_TYPE_UNKNOWN

Please advise how to fix this and actually download the ebook.