Friends can't connect to my servers with add-ons even though the internet connection is fine and the share add-ons button is active.

I have been trying to play with my friends on a server with add-ons which they were able to join many times before the recent update, now every time they try to join the loading bar gets to about half way before it tells them “connection to the host was lost”. We have tried everything from restarting our wifi's to deleting and reinstalling the game itself and nothing seems to be working.