Content Security Policy (CSP) Support
Some websites may have additional security protections using a technology called Content Security Policy (CSP). You can read more about CSP if you are curious.
Olark supports CSP out of the box, you can find the code on your Install page. Make sure to include the Olark snippet in its own file, and use a script tag's src attribute to include it (rather than embedding it in its own script tags, like the usual code).