Authoring dialog errors and doesn't allow the dialog field event handlers to work (AEM 6.2)

Hi,

I am writing a custom component with event handlers (Touch UI - Using AEM 6.2. ) for dialog fields using the example provided. Whenever I launch the dialog on any component, I am getting the error - "coralui2.js:12588 Uncaught TypeError: Cannot read property 'selectedIndex' of undefined" and I believe this stops the events are getting registered or triggered. 

Error is appearing when the below highlighted line of code runs - 
getValue: function () {
if (this.options.multiple) { // multiple returns array
return this._tagListWidget.getValues();
} else if (this.options.type === 'static') { // static
return this._nativeSelect[0][this._nativeSelect[0].selectedIndex].value;
} else if (this.options.type === 'dynamic') {
return this._valueInput.val();
} return null;},

We don't see this error when loading the page and this highlighted line of code runs fine. We have this error on all component dialog boxes and on all local instance and on our test instance. 

Please can you advice if you have encountered this issue before?