What causes random navigation crashes when using Shell routing?

Typical causes: unregistered or duplicate routes, wrong absolute versus relative URIs, passing complex objects via query strings, concurrent GoToAsync calls, or exceptions during page or ViewModel construction. Register routes and pass IDs or use a shared service to hand over complex data.

Register and navigate:

Routing.RegisterRoute("details", typeof(DetailsPage));
await Shell.Current.GoToAsync("details?itemId=123");