Can't see another's shared calendar events
My wife has been sharing a calendar with me. Until a few days ago I had been able to view events in it. Now I don't receive any new events but can still see the old ones. She has tried unsharing and then sharing again. I get her invite and accept. Her calendar appears again in my sidebar but I still don't see any new events. Any ideas? Thanks.
Mac Pro, OS X Mountain Lion (10.8.5)