What is the cache and why do we need to 'clear' it?

The 'cache' is a temporary place to keep a copy of information for faster retrieval on the second request for the same information. As we have just upgraded PowerSchool, your Mac is trying to retrieve data that no longer matches what PowerSchool is now looking for. So, we have been advised to clear the cache and then have another go at 'getting in'. Once cleared (see below), restart your Browser and the login to PowerSchool. From there, you're good to go.