It just started doing this today, out of the blue. The iCal window starts to load, and then immediately crashes, every time. I've already tried a reboot. What should I do to fix this? I do have the calendars backed up on Google, so I can reimport them if I need to. Is it safe to delete everything in ~/Library/Calendars/ ? EDIT: Never mind...after a little experimentation I discovered that something in ~/Library/Caches was causing the problem. I deleted the whole caches folder and iCal starts right up.