I can't log-in to Class on my Mac.
When I click the Login button, nothing happens or it displays an error.
Class supports all common Mac OS browsers. However, other applications can interfere with the login process. One of these is the 1password browser plugin and software.
Class does not support the functionality that 1password uses to access the website.
You will need to turn off 1password plugin for the browser.
For example, if you use Chrome, turn off the plugin in 1password to Chrome, then you should be able to access Class through Chrome in Mac OS.