Hi Jeffrey, Firefox can't display Word file attachments, but when downloading, it can save them or send them to a local installation of MS Word. What happens when you tell Firefox to download them? Is there a specific error message? ''Some mail sites and document storage sites may show a PDF preview of Word documents as an overlay in the tab, or in a new tab if you choose to view instead of download.'' Or if the problem is with Office online, what happens when you try to view a Word document in Office online? Is there a specific error message?