That is great! Now, about that broadcast, it may not be the main issue as per what the nature of the error is:
TypeError: null is not an object (evaluating 'content.textContent')
undefined : 3
Can you post the lines of code that was added into the main.js file?
If not possible, try to check the value that is being broadcasted. It could be behaving differently when executing silently. I would imagine that it is extracting a property or value from a result / object - however, during this time, it may not be available yet.
An example would be:
// below line of code would throw out an error when the 'eventResponse' is null
Then for the $rootScope broadcast. depending on the location of your controller declaration, you should be able just $scope instead. This is normally the case when the child controller is encapsulated by the Parent HTML with the MainCtrl.