Cause

The UITableViewController does not ‘live’ in a UINavigationController

Solution

Because I am using storyboard, the solution is slightly different from non-storyboard project.

Original structure is that a TabBarController owns two custom controllers. The first controller is a subclass of a UITableViewController.

To fix the problem, I have to

1) drag a UINavigationController in between the TabBarController and the First Custom Controller.

2) Remove the original ‘relationship’ segue between TabBarController and the First Custom Controller

3) Add a relationship between the TabBarController and the new UINavigationController

4) Add a relationship between the new UINavigationController and the new First Custom Controller