We not using Calendar functions inside missive, because we working with Calendar App of macOS etc. So if we got an attached invite .ics file and i want it to open on macOS, everything works fine and i can add it to my calendar. But if i want to open this file trough iOS i need to download it first, then i need to open my drive app, and add the .ics file to my calendar. It worked before you updated to the new attachment update few weeks/months ago and it's really annoying not being able to just add a calendar invitation to my own external calendar app as usual! Thanks for fix this!