[TIMOB-19137] Windows: Showing an alert dialog when another alert dialog is on screen throws runtime error

// this sets the background color of the master UIView (when there are no windows/tab groups on it)
Titanium.UI.setBackgroundColor('#000');

//
// create base UI tab and root window
//
var win1 = Titanium.UI.createWindow({
    backgroundColor:'#fff'
});

var label1 = Titanium.UI.createLabel({
	color:'#999',
	text:'I am Window 1',
	font:{fontSize:20,fontFamily:'Helvetica Neue'},
	textAlign:'center',
	width:'auto'
});

label1.addEventListener('click', function(){
	alert('hi');
	setTimeout(function(){
		alert('hi2');
	},1000);
})

win1.add(label1);

win1.open();