I try to install the standard php myadmin web module and get Fatal Error!
Failed to install web app : Could not find PHP version for /home/xxx/public_html/phpmyadmin
note I replaced the server name with xxx here
That sounds like a problem. I’ve never heard of erpnext, but if it’s installing custom stuff, or modifying configuration, you’ve probably got your work cut out for you. You need to figure out what it’s doing differently from the standard OS packages in a fresh install that’s breaking Virtualmin. PHP works fine when Virtualmin is installed as documented.
The nginx config file error seems to indicate the nginx version is not a standard OS package.
If they’re pulling in custom nginx and mariadb or doing something unusual with configuration, it probably won’t help to install it after. Something will probably still get broken. If you really need them to run on the same system, you’ll need to look into what both are doing.
Our installer, dependencies and configuration changes are all public in our github, you’d want to look at the Virtualmin-Config repo for the config changes, and the virtualmin-lemp-stack package for our dependencies…all of the packages we use, aside from our software, comes from the OS standard repositories. The lemp-stack package is derived from the virtualmin-lamp-stack-ubu repository, with an automated change to remove Apache deps and replace them with nginx.
You’re on your own wrt erpnext, I don’t know anything about it.