JQuery issue "TypeError: $.getJSON is not a function"

Thus happens commonly when migrating codebases from jQuery v1.x+ to v3.0+ as jQuery updated/deprecated/discontinued some of it's API.

I recommend using jQuery Migrate which will address this, along with other issues:

Get it here via CDN:

https://cdnjs.com/libraries/jquery-migrate

If using Gulp/Grunt, you can import into your project using

npm install --save jquery jquery-migrate

Github Repository - https://github.com/jquery/jquery-migrate

Read more about jQuery v3.0+.. http://blog.jquery.com/2016/06/09/jquery-3-0-final-released/

You seem to be using slim version of jquery which does not have the method getJSON thats why you are getting this error.

Please use the full version of jquery instead from the below link.

https://code.jquery.com/jquery-3.1.1.min.js

Slim version of jquery excludes ajax, animations effects etc