Check that you’re using CLASS with the Google Chrome browser. Class was developed for use on Chrome. Using CLASS on other browers such, as Safari or Mozilla Firefox, can result in CLASS not performing as usual.
Please note that if you access CLASS from a shortcut or link, it may be opening CLASS in a different browser. The best way to access CLASS is to open Google Chrome and then go to https://centre.classlaw.org.au. You may want to bookmark this page.