After upgrading Firefox, you might have gotten a prompt from your firewall. This was probably due to the Firefox Hello Video Chat feature.

For more info on Hello:
https://blog.mozilla.org/blog/2015/0...-as-in-person/

If you actually use it, that's fine. If you don't, you can disable Hello:

1. Open Firefox
2. Type about:config in the address bar, press enter
3. In the Search bar, type loop.enabled
4. Double-click loop.enabled to set value false

You can also remove the Hello icon (smiley face) from your navigation bar.

1. Open Firefox
2. Right-click on the navigation bar and click Customize...
3. Drag the Hello icon into the Additional Tools and Features box
4. Click Exit Customize