本地日历在iOS 10.2.1中消失

我有一个应用程序，我正在创build一个本地日历，以添加应用程序中显示的事件。检查事件types，然后添加事件的代码是标准的，如下所示：
if([eventStore respondsToSelector:@selector(sources)]) { for (EKSource* source in eventStore.sources) { if (source.sourceType == EKSourceTypeBirthdays){ localSource = EKSourceTypeLocal; break; } }

在iOS 10.1中，打印事件源显示设备中存在的所有日历以及应用中存在的本地日历，如下所示：

EKSource <0x1700c6e40> {UUID = 6B5927E7-78D6-418B-82D3-C06821A51758; type = Local; title = Default; externalID = (null)}, EKSource <0x1700c6740> {UUID = DE256E79-E778-44EA-99F9-0C28374F043C; type = Other; title = Other; externalID = (null)}, EKSource <0x1700c6190> {UUID = 9F735DC3-43D5-4F94-84D5-76AF832B3CB3; type = CalDAV; title = iCloud; externalID = 9F735DC3-43D5-4F94-84D5-76AF832B3CB3}, EKSource <0x1700c5ef0> {UUID = 0B41FF62-42A6-4C21-9B3F-FDB331819FBF; type = Exchange; title = abjf; externalID = 0B41FF62-42A6-4C21-9B3F-FDB331819FBF}, EKSource <0x1700c6120> {UUID = 7EFAED86-88D5-44C8-978F-B4CF6E06514D; type = Subcribed; title = Subscribed Calendars; externalID = Subscribed Calendars

但是在iOS 10.2中，打印事件存储源是遵循源的
EKSource <0x1702c3790> {UUID = B8DCA3DF-B89F-4AD5-B923-8D8298ECE36F; type = Exchange; externalID = B8DCA3DF-B89F-4AD5-B923-8D8298ECE36F}, EKSource <0x1700d89c0> {UUID = 4530AC67-D8C6-42EC-B485-3622AE25C23B; type = CalDAV; title = iCloud; externalID = 4530AC67-D8C6-42EC-B485-3622AE25C23B}, EKSource <0x1702c36b0> {UUID = A4F12149-4FB7-4852-9F73-E573CEA73CA0; type = Other; title = Other; externalID = (null)}

本地日历正在从事件库中消失，因此事件不会显示在应用程序中。

其他人在iOS 10.2.1中面临同样的问题吗？ 非常感谢帮助。