Well the (renewed) server was running fine, under Ubuntu 18.04 and Webmin 1.930 combined with Virtualmin 6.07. The vast majority of panels will complain if you upgrade Ubuntu to version 19.04. Only TinyCP continued to run seamlessly. I can now conclude that the latter also applies to Virtualmin and Webmin. We have arrived in the Disco version of Ubuntu again! Immediately installed PHP version 7.3 and discovered how you can link a certain website to a certain PHP version in Virtualmin. Everything I have now runs fine under PHP 7.3, but I know there is software out there that runs best on version 5 of PHP. We are now prepared for that as well. It's looking good, all in all...