I have a .ics file that works with outlook gmail and any calendar I tried. Mac calendar does not display errors but as a matter of fact it doesn't save the event. Obviously the file header type is text/calendar. Need help to get what is missing here.
BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//Technology//NONSGML Calendar//EN
CALSCALE:GREGORIAN
METHOD:PUBLISH
BEGIN:VEVENT
UID:20190218T094757-1209729636
CLASS:PUBLIC
X-MICROSOFT-CDO-INTENDEDSTATUS:BUSY
ORGANIZER;CN=robert:MAILTO:abc@[login to view URL]
DTSTAMP:20190218T094757Z
DTSTART;TZID=America/Panama:20190227T070000
DTEND;TZID=America/Panama:20190227T093000
LOCATION:berlin
SUMMARY:test
TRANSP:TRANSPARENT
END:VEVENT
END:VCALENDAR