on IOS13 ,the log was:
17:41:23.853 Babylon.js v4.0.3 - WebGL1
17:41:23.876 IP or host change
17:41:23.899 load car info
17:41:23.932 BJS - [17:41:23]: Unable to load from …/scenes/highway/Highway.babylon: importScene of undefined from undefined version: undefined, exporter version: undefinedimportScene has failed JSON parse
17:41:24.859 IP or host change
17:41:24.880 127.0.0.1