Explain: NS_ERROR_XPC_SECURITY_MANAGER_VETO

Has anyone ever seen this javascript error in Firefox Console?

NS_ERROR_XPC_SECURITY_MANAGER_VETO

I was looping throuhg a set of class using jquery when I saw this error.

I was using each() function like this:

function RemoveOldChats(LastID){
	alert('1');
	$('.chat_msg_item ').each(function(){
			var loopIdNow =  parseInt( $(this).attr('id' ).replace(IdPrefix,''));
			alert('loopIdNow = '+loopIdNow);
		if( loopIdNow > ( parseInt(LastID) + 3) ){
			//$(this).remove();
			alert('remove the last 20');
		}
		alert('loop');
		
	});
	alert('1ast');
}

Can any one help me explain?