Using older versions of Outlook for Mac for personal email and calendar
Hi there,
What mail application you & organizer using?
It's not possible you will get canceled meeting unless meeting organizer did that.
It seems that the organizer send a meeting cancellation that will remove the meeting from your calendars.
It depend how did he update or cancel a meeting he organized.
You can try to create and update meetings in Outlook Web App to check if you still have any problem.
Thanks,