Error message on ADE ""error getting license. license server communication problem: e_google_device"

Hi, 

I am getting the following error message "error getting license. license server communication problem: e_google_device_limit_reached" when I try to convert ASCM to EPUB. Support won't help me because I am not a subscriber. Suggested I post here. 

I don't know why this is happening and can't find any helpful information on how to rectify this. Thanks