I have a very important calendar invite to respond to and I can't. It is a .ics attachment emailed from Outlook. When I double click on it the event populates in Calendar, but I can't respond. I added the email address to the "Me" contact card in Contacts, I clicked on "Make this my Card" in contacts, and added the necessary email to my contact. After doing all that I can right click on the event and see accept, maybe, decline, and report junk. Report junk is checked, and it won't let me click on accept. Help?