This can occur due to incorrect proxy settings in the web browser for Avast

Resolution: Include the Proxy server settings for Internet Explorer when using broadband and/or local area network (LAN) Internet connection

  1. Start Internet Explorer.
  2. Select Tools → Internet Options… from the main menu.
  3. Switch to page Connections.
  4. Click on the LAN Settings… button.
  5. Check the option Use a proxy server for your LAN.
  6. Write localhost into the Address field (alternatively, you can enter IP address 127.0.0.1, which is the same as localhost).
  7. Enter 12080 into the Port field.
  8. Confirm with OK button.

Screenshots provided below:

Have a wonderful day. Good Karma!