.ics files - outlook meeting.ics attachment won't open

My Iphone can't open outlook meeting invitations. It shows up in email as a meeting.ics attachment that will not open.

The old blackberry did it perfectly, was sent as meeting info with no meeting.ics folder to open (in this case not open)

This is an extremely basic yet important function that should be elementary to any business enterprise phone.

What am I doing wrong?