Uncaught ReferenceError: $ is not defined - Datepicker - Codeigniter 3

One problem might be the use of the "defer" attribute with the <script> elements. This means that jQuery won't load until after all the other html loads.

But this bit of code will try run as soon as the view is loaded.  

Code:

$( "#datepicker" ).datepicker({inline: true});

Of course, it fails - jQuery hasn't loaded yet so $ is not defined.

Remove the defer attr from the <script> tags and see if that helps.

You might get new errors that we can address later.