Cannot download ePUB books to ADE 1.7.2, or v2.0

When I attempt to download an ePUB book to Adobe Digital Ed (I am using v 7.1.2, but have had same issue with later versions), the book does not appear in the ADE library in any form. This occurs with any book I try to download. Using Firefox 33.0.3.  Attempted to replace versions of ADE; same result. Prefer to use old version as compatible with my ePUB converter program. Had been successful for years in the past. Mac OSX, Firefox 33.0.3