Opening MS Word documents never used to be a problem: double click and it opens in my Win10 / Office 2003 application. Since about a month (I am now on TB 91.5.0) opening '''.docx attachments''' is problematic: After double click, instead of opening the attachment in Word, a window opens to save the document, but without any suggested file-name. Opening '''.doc''' attachments is still fine, they open in Word. What I see in the Message Source is that .doc attachments have "Content-Type: application/msword;". But .docx attachments have "Content-Type: application/vnd.openxmlformats-officedocument.wordprocessingml.document;". My question: How can I instruct TB to open .docx documents in Word? Thanks!