Accounts can only be part of one Family at a time.
I just upgraded my Mac Book Pro to Yosemite and get the following error when trying to start up Family Sharing
{my appleID} "is used for sharing purchases in another Family. Accounts can only be part of one Family at a time." I'm not sure what that means or how to fix it. I'm only part of one family! I get the same error message trying to start up Family Sharing on my iPhone and iPad.
MacBook Pro, OS X Yosemite (10.10)