Drupal 8.1.1 Clean URL's Not possible

I have gone through every piece of documentation and tutorial and for the life of me I can not get clean URL’s enabled!

Could someone please provide some guidance or assistance?

Our organization is considering from making the switch from Ektron to Drupal so we really want to test it out. This feature is important to us, and a decision making factor so it’s crucial we get it working.

Drupal version: 


Source: https://www.drupal.org/taxonomy/term/22/feed