I have an issue with the same symptons. Installed on Ubuntu 18.04 with instructions from here: http://www.webmin.com/deb.html From log Mar 24 08:01:32 cloudb-2019 systemd[1]: Starting LSB: web-based administration interface for Unix systems... Mar 24 08:01:34 cloudb-2019 perl[957]: pam_unix(webmin:auth): authentication failure; logname= uid=0 euid=0 tty= ruser= Mar 24 08:01:35 cloudb-2019 webmin[957]: Webmin starting Mar 24 08:01:36 cloudb-2019 systemd[1]: Started LSB: web-based administration interface...