Question: When I try to get the identifier of an EKEvent, all I get is a nil value. Since in iOS5 EKEvent is a subclass of EKCalendarItem, I figured I might be able to get the EKCalendarItem's UUID, but that returns nil as well. 

Every now and then I also get this error while trying to access the identifier or UUID property: 

```
CADObjectGetInlineStringProperty failed fetching uniqueID for EKPersistentEvent with error Error Domain=NSMachErrorDomain Code=268435459 "The operation couldn’t be completed. (Mach error 268435459 - (ipc/send) invalid destination port)"

```

I've been stuck on this problem for quite some time now, but figured it would be iOS5 beta related. But since we're now at iOS5, it's still not working.

Answer: 
eventIdentifier is set when the event is added to the EKEventStore. If you try to access this value before adding it, it would return null.
The EKEvent eventIdendifier isn't generated until the event is saved. You can access/store the eventIdentifier after you've saved the event to the EKEventStore

```
    [store saveEvent:event span:EKSpanThisEvent error:&err];
    NSString *eventIdentifier = event.eventIdentifier;

```