Google Calendar "Unable to launch event" - caused by missing DTSTAMP

For several years, Google's product help forums have been littered with people trying to download a .ics event from their email, only to receive the error "Unable to launch event" when trying to add it to Google Calendar. It doesn't happen with all iCal attachments, only some. Here's how to fix it. I checked dozens of broken iCalendar invites using this iCal validator and they all had the same problem: "Missing DTSTAMP property". Here's a typical broken file: BEGIN:VCALENDAR VERSION:2.0 PRODID:abcdef-ghij-klmn-opqrs-tuvwxyz BEGIN:VEVENT DTSTART:20260713T093000Z DTEND:20260713T103000Z SUMMARY:Your Delivery (Order 123456789) UID:83c510fa-1be4-48a2-8338-c5a2350ba6e5 END:VEVENT END:VCALENDAR If you read the specification or follow the flowchart you'll see: Property Name: DTSTAMP Conformance: This property MUST be included in the "VEVENT", "VTODO", "VJOURNAL", or "VFREEBUSY" calendar components. Adding that to the above produces: BEGIN:VCALENDAR VERSION:2.0…