Cannot read property 'push' of null

I am running into a bug with the navController in my code. My code is based on the conference template.

In my app.component file, I have defined a new side menu for one of the tabs. Lets called this tab, tab x. Tab x has a side menu with buttons. The buttons are supposed to push a new page on top of the navigation stack. I realized I couldn’t directly have the buttons navigate from the side menu because this pushes the page above the tabs page. I want to push on top of the tab x.

To get around this, I wrote an event listener in the side menu in the app.component file to publish when click. The tab x page is listening for this event, and when it is fired, it pushes the page I want to navigate to on top of tab x.

This where the bug occurs. The bug refers to the navController.push() line. The exact error states the following:
ERROR TypeError: Cannot read property ‘push’ of null
at Tab.NavControllerBase._queueTrns (nav-controller-base.js:203)
at Tab.NavControllerBase.push (nav-controller-base.js:70)

Strangely enough, this error only occurs when I edit the code and ionic serve rebuilds the app. If I refresh the page with ctrl+r, then the code works as expected.

Any idea on how to get past this bug?

When you restart, the nav stack isn’t the same. I’d close the browser in between restarts, to avoid any caching issues.