Check to see if your camera or microphone work on another browser

You may be experiencing a browser issue if you have not allowed access to your camera and microphone

It might be that you have allowed access to your camera and mic one on browser but not another. Either way, make sure it's a browser issue and not a problem with your camera or microphone and switch browsers and see if they work on another one. If you are using Chrome, switch to Firefox and vice versa. 

If you are experiencing mic issues on Chrome, go to your Settings to see if you need to update: chrome://settings/help