It seems strange to me that when I go to other users' examples and overwrite with my html code, I alter the external sources. My jsFidle example works. On the contrary, if I'm in my account starting a jsfidle from scratch it doesn't work for me even checking the JAVASCRIPT (gear) config.
Example of a random Jsfidle in which I overwrite with my code and external material:
This other one is my jsfidle from scratch, they are the same external resources and configurations in the javascript:
Maybe someone helps me see what my ignorance is in this.
The problem is that you are calling your libraries without the https protocol, browsers do not allow cross resources, that is, if the page is being called through https as jsfiddle: https://jsfiddle.net/nacs2025/qpn5L34j/
You cannot call your libraries through http:
http://maxcdn.bootstrapcdn.com/bootstrap/3.3.6/css/bootstrap.min.css
To solve the problem change the urls of your libraries to urls that are through https.
Here is a functional jsfiddle based on yours: https://jsfiddle.net/59cd635k/
For more information check:
https://developer.mozilla.org/es/docs/Web/HTTP/Access_control_CORS