I searched through the Outlook options over and over again, but without success. Before updating Office 365 recently I was able to see HTML-formatting in the description field of an ics-file. After the update I only see plaintext, as I found out today. I can't find any hint on the web that the X-ALT-DESC property is not supported anymore thus I assume it should still be working.
Can you please help me get the HTML view back?