There's been a recent major revision of the ECMAScript (also called JavaScript) security standards which many websites and the latest web browsers have adopted. This means that for not-so-old web browsers many web sites are now broken (you should be able to see the javascript error in the browser console). Your choices are to either upgrade to the latest web browser, or use an ancient web browser and hope the web site developers have catered for both old and new. Unfortunately not-so-old web browsers are currently not being catered for.
This issue is an annoying pain. In my case to upgrade my Safari browser to the latest version I need to install a whole heap of MacOSX patches before I can upgrade Safari. It's easier to just download and install Firefox until I get around to scrubbing the disk and installing the latest MacOSX rather patching the old one.