Hi I've found that there are some packages missing in Howto: apt-get install wget gnupg2 lsb-release ufw
It would be best if you had used the auto-installer, as recommended in that guide: https://www.howtoforge.com/ispconfig-autoinstall-debian-ubuntu/ No packages are missing when using the minimal server guide https://www.howtoforge.com/tutorial/debian-minimal-server/ (as mentioned in perfect server) plus the perfect server guide, and there are also no packages missing when using minimal server guide plus the auto-installer guide. So its just that on your base server these packages have been removed and were missing therefore later. I'll add them to the guide as it will still work even when they are there.
