Jake,
Sorry to hear you're having problems. Can you give me any additional information about the crash, such as:
- does it happen with a mapView or SceneView (or both)?
- does it happen during any particular operation/task/user input?
- is there any particular layers/maps/scenes/basemap/data that causes it to happen more often or not?
- any particular device (example: iPhone 6 or 7s or iPad)?
- any particular iOS version?
The method in question is called when there are changes to the map/scene that would require updating the attribution text; things such as adding/removing layers, changing base map layers, and just updating the visible area of the map/scene (as different data may become visible/hidden).
Mark