You've just joined the classroom and received an error that another program is using your camera or microphone. The good news is that this issue is self-explanatory and is a really easy fix.

This just means that another application on your computer is currently using your camera or microphone. Your computer doesn't let multiple applications use the camera and microphone at the same time, so we end up with this error.

The first thing to do is check if you have any applications, like Zoom or Google Meet, open on your computer. If you do, close them and double check you have no other applications open that could use your camera & microphone.

Give the page a refresh, and voila! The error should be fixed.

It's still not fixed...

Sometimes, applications will hold onto your camera and microphone after shutting down, making this problem slightly harder to fix. Usually, your best bet is to just restart your device, as that'll force them to shut down properly.

Alternatively, open Task Manager, select the programs you think are using your inputs and force-close them through there.