Some web applications work better on certain browsers. You can eliminate many common issues by using a different browser when a website or web application isn't working.
Viticus Group Support Center
Try one of these common browsers.
1. Microsoft Internet Explorer
To install Chrome - https://www.google.com/chrome/
To install Firefox - https://www.mozilla.org/en-GB/firefox/new/
It might also be worth trying to view the website on one of your colleague's computers.