Thanks Sergiy. Below are the results I found. I dont see much problem, for eg. the Console shows some info not error. Let me know if you can make out any errors from the below. 2 of my colleagues tried this lesson and had the same problem, we compared it with the CRUD app, but since the CRUD app is a plugin, we feel its not well explained (since this is crucial, may be good to highlight this to your documentation team.). Any help is much appreciated.
Synchronous XMLHttpRequest on the main thread is deprecated because of its detrimental effects to the end user's experience. For more help, check https://xhr.spec.whatwg.org/.
send @ jquery-2.1.1.js:8554
If you need anything else in particular, let me know, as it doesn't look like an error done by developer but a shortfall in the instructions.