我将数据保存在来自服务器的本地数据库中 . 我使用NSFetchedResultsController来显示数据 . 但我得到一个错误“ CoreData: error: Serious application error. An exception was caught from the delegate of NSFetchedResultsController during a call to -controllerDidChangeContent:. attempt to insert row 12 into section 1, but there are only 12 rows in section 1 after the update with userInfo (null)". 并且列表被破坏 . 如屏幕截图所示 .

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请提出原因

core-data ios7 nsfetchedresultscontroller