核心数据无效行数错误，无需插入/删除行

Question

我在选择UITableViewCell时修改（但不添加或删除）Core Data存储中的对象。但是，每当我这样做时，我都会收到以下错误：

CoreData: error: Serious application error.  An exception was caught from the delegate of 
NSFetchedResultsController during a call to -controllerDidChangeContent:.  Invalid update: 
invalid number of rows in section 0.  The number of rows contained in an existing section 
after the update (5) must be equal to the number of rows contained in that section before 
the update (5), plus or minus the number of rows inserted or deleted from that section (1 
inserted, 0 deleted) and plus or minus the number of rows moved into or out of that 
section (0 moved in, 0 moved out). with userInfo (null)

...除了我没有插入或删除任何新行外，我刚刚修改了备份行的现有对象的属性。我该如何解决这个错误？