iOS Apprentice MyLocations code problems

I entered all the code for MyLocations up to Locations Tab. The program compiles but it had a fatal error as indicated in my previous post viz

In AppDelegate.swift

var window: UIWindow?

let tabController = window!.rootViewController as! UITabBarController

Thread 1: Fatal error: Unexpectedly found nil while unwrapping an Optional value

I would appreciate any advice.

did you find any solution?

@syktek @saipurva Do you still have issues with this?