Pages or charts not loading

The course works in current versions of Chrome, Edge, Firefox and Safari, on computers, tablets and phones.

1. Refresh the page (Ctrl+Shift+R, or Cmd+Shift+R on a Mac).
2. Turn off browser extensions that block scripts for this site.
3. Try a private window or another browser.
4. Check the system status page.

Still stuck? Contact support; we automatically include your browser details so you don't have to describe them.