Undefined view for Ext.appController

I am starting to convert my Ext 4.2 programs to 5.1. When trying to display a panel, I get an error because the view value is undefined in

var name = Ext.app.Controller.getFullName(view, 'view', this.$namespace)

which is callled by the dispatch function in Ext.app.domain.Component when firing an add event on the panel.

This is being called on a controller that extends Ext.app.Controller so it does not have a view value. What am I doing wrong?

Undefined view for Ext.appController