iCloud calendars listed multiple times
I just updated my MBP (15" mid-2012) to El Capitan (from 10.8.5). I initially had the "moving calendars to server" problem that others have reported; I was able to resolve that by deactivating and reactivating my iCloud account as suggested elsewhere but somehow in the process now all of my iCloud calendars are listed multiple times (9!) in the Calendar sidebar and all of my events show up 9 times. So in other words, 9 Work calendars, 9 Home calendars, etc. This includes calendars just used by me, one shared calendar, and several that I'm subscribed to. (Non-iCloud calendars (e.g. "Found in Mail") are fine.) The calendars aren't actually duplicated in iCloud; they show up normally on my iPhone and my MacBook. If I add an event to one calendar, it shows up in all 9 of the listings for that calendar and syncs fine to my other devices. So it appears that the calendars themselves are ok but are being displayed multiple times on my MBP. I can deal with the clutter on the display by unchecking 8 of the 9 listings in the sidebar, but that's a clunky fix and I'd like to get things back to normal. I've searched here and elsewhere and haven't been able to find a similar problem reported anywhere. Any suggestions? Thanks!
MacBook Pro, OS X El Capitan (10.11.5)