Internal Pages stuck on eternal loading

This is the second website I’ve had troubles with, so there may be something on the server side, but when I navigate to the internal pages (either when logged in or not), I get stuck on an endless loading loop — you can go have a look for yourself!

Any advice would be greatly appreciated, even if it’s how to best google a solution — research is my Achilles heel. I don’t have access to the server side, but I can send messages along to my coworker who does.

The page I need help with: [log in to see the link]