QML EXC_BAD_ACCESS crash

import QtQuick
import ...

Window { id: root
   ...
   QtObject { id: sessionManager
      ...
      signal ooSignInNotification(int notificationType, string errorCode)
      ...
      function handleSigningOut()
      {
         modalLayer.showModal(C.ModalLayer.OoSignIn)
         ooSignInNotification(C.NotificationType.Info, qsTr("You have been signed out."))
      }
      ...
   }
   ...
   Item { id: modalLayer
      property int activeModalLayer: C.ModalLayer.None
      ...
      Loader { id: modalLoader
         ...
         sourceComponent:
         {
            switch (modalLayer.activeModalLayer)
            {
            ...
            case C.ModalLayer.OoSignIn:
               return ooSignInModalLayerComponent
            ...
            }
         }
      }
      ...
      Component { id: ooSignInModalLayerComponent
         FocusScope {
            focus: true
            ...
            OoSignInLayer { id: ooSignInLayer
               ...
               Component.onCompleted:
                  sessionManager.ooSignOutNotification.connect(showNotification)
               ...
            }
         }
      }
      ...
      function showModal(newModalLayer)
      {
         activeModalLayer = newModalLayer
         visible = true
      }
   }
   ...
}

import QtQuick

FocusScope { id: root
   ...
   QtObject { id: my
      property int notificationType: C.NotificationType.None
      ...
   }
   ...
   function showNotification(type: int, message: string)
   {
      my.notificationType = type // The debugger gets stuck here
      notificationMessage.text = message
      usernameField.forceActiveFocus()
   }
   ...
}