I only see “loading” for every asset on the trading page

Your session may have expired. Try refreshing the page and logging in again.
You may have trouble caused from your local firewall or proxy server. Go to websocketstest.com and see the results of WebSockets (Port 8080) test. If you do not see green checkmarks for all aspects of that test then you likely have an issue with your firewall or proxy server. In this case speak to your web administrator as you need to be receiving over Port 8080.