The browser plugins for Safari and Chrome no longer install automatically. I realise that the Chrome extension is available in the Chrome store, but the Safari one is buried away in a folder /Library/Application Support/Avast/store/AOS/Payload and I have to copy this elsewhere and then install manually. Can this issue be fixed at some point?
Install the latest version and see if thinks are working.
https://forum.avast.com/index.php?topic=163270.msg1346283#msg1346283