Network requests can fail, permissions to files can be missing... More generally, errors happen. By default we handle every unhandled exception or unresolved promise and show error screens. However, you should handle the "expected" error cases for your command. You should aim to not disrupt the user's flow just because something went wrong. F.e. if a network request fails but you can read the cache, show the cache. A user might not need the fresh data straight away. In most cases it's best to show a Toast with information about the error.