All domains stopped working. Connection refused error.

Hi, I had a couple websites running smoothely as virtualhosts for over a year, then I noticed the https certificate expired of one of the websites. Turns out the webmin keeps stopping. As I restarted it from SSH, it stopped again within minutes. So I decided to update ubuntu since I hadn't done that in a year. It also updated webmin. Now the webmin is not stopping but none of the websites are working.

For example: www.ateworldtalk.com returns 'connection refused'. From SSH I can see webmin is running. I've disabled firewall with ufw disable How do I find the cause of this error?