Daypilot Scheduler Event List has an event having id : "undefined"

Hi Daypilot team,
I'm using DayPilot Scheduler for my project.
After the scheduler initials by using "dpPrdPkg.init();"

Before I bind the Event list to "dpPrdPkg", I tried to print out by using 2 commands
console.log(dpPrdPkg.events.list.length);
console.log(dpPrdPkg.events.list);

the corresponding result is
console.log(dpPrdPkg.events.list.length); >> 0
console.log(dpPrdPkg.events.list); >> please see the screenshot I attached

P/s: here is my version of Daypilot js file
DayPilot Pro
Copyright (c) 2005 - 2014 Annpoint s.r.o.
http://www.daypilot.org/
Use of this software is subject to license terms.
Version: 1418