I have been utilizing Virtualmin together with Webmin on CentOS for more than a year. Now for the first time is going to try it on a remote Ubuntu server. However, before running install.sh I'd like to clarify are Webmin and Virtualmin really compatible?
I would not have such doubts if https://help.ubuntu.com/community/WebMin wouldn't state:
WebMin was in Ubuntu until 5.10 Breezy Badger, and was then dropped because it is not compatible with the way that Ubuntu packages handle configuration files, and caused unexpected issues with people's systems. See https://answers.edge.launchpad.net/ubuntu/+question/2873 for more background. Note that the Debian (and Ubuntu) policy and requirements for how packages deal with configuration files is stricter than other distributions, which makes package installs and upgrades more robust. See Configuration files in the Debian Policy Manual for more information.
Some other sources also indicate users had issues with the combination: