I have not been able to access my group calendar for over two weeks & I am the only moderator - please help!?

I have tried deleting cache, cookies, history, and refreshing the page I have tried accessing with different browsers and computers. I even created a new profile, but without success. All other features work, but not the group calendar. The other members of my group can access the calendar. My group is: http://groups.yahoo.com/group/SycamoreValleyHomeschool/ and the error message I receive is: Sorry, there was a network error, please try refreshing the page.