Mathjax in shiny suddenly stopped working

I have a brilliant application running on AWS with Ubuntu. It uses mathjax and has been working great for a couple of weeks. Today it just stopped rendering the mathjax code. I have not made any changes to the system or code. When I test my application locally I have the same problem. Has anyone had similar problems?

http://ec2-54-76-89-164.eu-west-1.compute.amazonaws.com:3838/Quizii Rekentoets