Hi Tigrrreyes or anybody who had that issue!
Did you find a solution to that? I have exactly the same issue and get pretty annoyed that I cannot import events any more. I thought it might be due to the fact, that outlook invitations are usually called "Mail Attachment.ics" and there is an issue when they are reneamed in the mail attachment folder to avoid duplicate names.... I am using apple and ical since 6 years now and there must be houndreds of these ical files in my mail folders.
Hi, Yu Haining.
MyMac tech support guy was able to do what the so-called Genius Bar at the Apple Store was not.
We traced the issue to redundant .ics archive files, from which iCal was apparently drawing randon .ics events.
To solve the issue, we:
1. Make a copy of your /Users/username/Library/Calendar folder as a backup
2. Go to iCal; export all of your calendars, by selecting them one at a time, then File -> Export to a .ics file
3. Quit iCal
4. Delete the contents of that initial Calendars folder (/Users/username/Library/Calendar)
5. Open iCal
6. Import Calendars one by one by going to File -> Import
7. Delete the iCal preference files in /Users/username/Library/Preferences/com.apple.ical* (multiple files starting with com.apple.ical…….)
I am happy -- and relieved -- to report that incoming meeting invites now behave properly.