This was on Rimuhosting, and the Vmin installs were by their support team:
Vmin GPL was installed and a domain created with Awstats. GPL was replaced by Pro. Upon trying to recreate a VS that had existed under GPL, an error was thrown about Awstats already being enabled for that domain.
Rimu support reports:
It looks like virtualmin doesn't clean up the awstats domains properly.
But that is easy to fix via the webmin interface (in "Servers"->"Awststs
Reporting") by deleting the domain at issue. after doing that I was able
to create the domain with awstats checked no problem."