Terminating app due to uncaught exception 'NSInvalidArgumentException', on deleting Row in UITableView [duplicate] - swift

Question

This question already has an answer here:
unrecognized selector sent to instance when no related entities found in Core Data
(1 answer)
Closed 4 years ago.
I am getting the above error when executing the following code:
func tableView(_ tableView: UITableView,
commit editingStyle: UITableViewCellEditingStyle,
forRowAt indexPath: IndexPath) {
let eventsOnArray = selectedRecipient?.events.allObjects // crashes here
guard let eventToRemove = eventsOnArray![indexPath.row] as? Event, editingStyle == .delete else {
return
}
managedContext.delete(eventToRemove)
do {
try managedContext.save()
getEvents()
self.eventList.reloadData()
} catch let error as NSError {
print("Saving error: \(error), description: \(error.userInfo)")
}
}
The detailed error is:
2018-03-11 12:20:49.732482-0400 Card Tracker[1516:29197] -[Recipient events]: unrecognized selector sent to instance 0x600000283840
2018-03-11 12:20:49.746477-0400 Card Tracker[1516:29197] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[Recipient events]: unrecognized selector sent to instance 0x600000283840'
*** First throw call stack:
(
0 CoreFoundation 0x000000010fe2f12b __exceptionPreprocess + 171
1 libobjc.A.dylib 0x000000010ef76f41 objc_exception_throw + 48
2 CoreFoundation 0x000000010feb0024 -[NSObject(NSObject) doesNotRecognizeSelector:] + 132
3 CoreFoundation 0x000000010fdb1f78 ___forwarding___ + 1432
4 CoreFoundation 0x000000010fdb1958 _CF_forwarding_prep_0 + 120
5 Card Tracker 0x000000010e62b773 _T012Card_Tracker010ViewEventsC10ControllerC05tableC0ySo07UITableC0C_SC0gC16CellEditingStyleO6commit10Foundation9IndexPathV8forRowAttF + 195
6 Card Tracker 0x000000010e62c177 _T012Card_Tracker010ViewEventsC10ControllerC05tableC0ySo07UITableC0C_SC0gC16CellEditingStyleO6commit10Foundation9IndexPathV8forRowAttFTo + 119
7 UIKit 0x0000000110410a5f -[UITableView _animateDeletionOfRowAtIndexPath:] + 177
8 UIKit 0x0000000110419a59 __82-[UITableView _contextualActionForDeletingRowAtIndexPath:usingPresentationValues:]_block_invoke + 59
9 UIKit 0x0000000110953d67 -[UIContextualAction executeHandlerWithView:completionHandler:] + 174
10 UIKit 0x0000000110c41374 -[UISwipeOccurrence _performSwipeAction:inPullview:swipeInfo:] + 702
11 UIKit 0x0000000110c42bd1 -[UISwipeOccurrence swipeActionPullView:tappedAction:] + 112
12 UIKit 0x0000000110d25ed2 -[UISwipeActionPullView _tappedButton:] + 138
13 UIKit 0x00000001102ae972 -[UIApplication sendAction:to:from:forEvent:] + 83
14 UIKit 0x000000011042dc3c -[UIControl sendAction:to:forEvent:] + 67
15 UIKit 0x000000011042df59 -[UIControl _sendActionsForEvents:withEvent:] + 450
16 UIKit 0x000000011042ce86 -[UIControl touchesEnded:withEvent:] + 618
17 UIKit 0x000000011089ebad _UIGestureEnvironmentSortAndSendDelayedTouches + 5560
18 UIKit 0x0000000110898a4d _UIGestureEnvironmentUpdate + 1506
19 UIKit 0x000000011089841f -[UIGestureEnvironment _deliverEvent:toGestureRecognizers:usingBlock:] + 484
20 UIKit 0x00000001108974cb -[UIGestureEnvironment _updateGesturesForEvent:window:] + 288
21 UIKit 0x0000000110325f14 -[UIWindow sendEvent:] + 4102
22 UIKit 0x00000001102c9365 -[UIApplication sendEvent:] + 352
23 UIKit 0x000000012c2fe49d -[UIApplicationAccessibility sendEvent:] + 85
24 UIKit 0x0000000110c15a1d __dispatchPreprocessedEventFromEventQueue + 2809
25 UIKit 0x0000000110c18672 __handleEventQueueInternal + 5957
26 CoreFoundation 0x000000010fdd2101 __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__ + 17
27 CoreFoundation 0x000000010fe71f71 __CFRunLoopDoSource0 + 81
28 CoreFoundation 0x000000010fdb6a19 __CFRunLoopDoSources0 + 185
29 CoreFoundation 0x000000010fdb5fff __CFRunLoopRun + 1279
30 CoreFoundation 0x000000010fdb5889 CFRunLoopRunSpecific + 409
31 GraphicsServices 0x00000001159789c6 GSEventRunModal + 62
32 UIKit 0x00000001102ad5d6 UIApplicationMain + 159
33 Card Tracker 0x000000010e606727 main + 55
34 libdyld.dylib 0x000000011436dd81 start + 1
35 ??? 0x0000000000000001 0x0 + 1
)
libc++abi.dylib: terminating with uncaught exception of type NSException
(lldb)
I am trying to delete a detail row in a Header-Detail based Entity. The crash occurs in the debugger as soon as I leave the line let eventsOnArray. I have placed a break point on that line, the code runs up until that point and then crashes when I use "Step Over".
getEvents:
func getEvents () {
// Now load all Events for this Receipient
let request = NSFetchRequest<NSFetchRequestResult>(entityName: "Event")
request.resultType = .dictionaryResultType
do {
events = try managedContext.fetch(request) as! [NSDictionary]
} catch {
print("Core Data Fetch Failed:", error.localizedDescription)
}
}
Core Data Definition:

Answer 1

Chances are that selectedRecepient is not an instance of Recipient class (or at least ObjC runtime thinks so).
Try to examine its type:
print(type(of: selectedRecipient))
If it prints NSManagedObject then you should make sure that Recipient entity has its class set to Recipient in data model editor – this tells Core Data to cast instances of that entity to the corresponding class.