Missing packages and repos setting up webmin on VPS

I'm just trying to set up webmin as the first thing on a new VPS, I'm familiar with Ubuntu (it's my main work machine). This is what's on the VPS Description: Debian GNU/Linux 8.5 (jessie) Release: 8.5 Codename: jessie So I follow the instructions to download and install virtualmin: wget http://software.virtualmin.com/gpl/scripts/install.sh sudo /bin/sh install.sh It starts well but eventually fails: [INFO] Started installation log in /root/virtualmin-install.log ▣□□ Phase 1 of 3: Setup Installing extra dependencies for Debian 8 [ ✔ ] Downloading apt.gpg [ ✔ ] Adding GPG key for PHP7 packages [ ✔ ] Downloading RPM-GPG-KEY-virtualmin-6 [ ✔ ] Downloading RPM-GPG-KEY-webmin [ ✔ ] Installing Virtualmin 6 key [ ✔ ] Installing Webmin key [ ✔ ] Updating apt metadata [ ✔ ] Downloading repository metadata [ ✔ ] Disabling cdrom: repositories [ ✔ ] Cleaning out old metadata [ ✔ ] ▣▣□ Phase 2 of 3: Installation Installing Webmin [ERROR] Failed with error: 100 [ ✘ ] [ERROR] Something went wrong. Exiting. [ERROR] The last few log entries were: Reading state information... Some packages could not be installed. This may mean that you have requested an impossible situation or if you are using the unstable distribution that some required packages have not yet been created or been moved out of Incoming. The following information may help to resolve the situation: The following packages have unmet dependencies: webmin : Depends: libauthen-pam-perl but it is not installable Depends: libio-pty-perl but it is not installable Depends: apt-show-versions but it is not installable E: Unable to correct problems, you have held broken packages. ###### Here's what sources.list looks like deb http://security.debian.org/ jessie/updates main contrib deb-src http://security.debian.org/ jessie/updates main contrib # jessie-updates, previously known as 'volatile' # A network mirror was not selected during install. The following entries # are provided as examples, but you should amend them as appropriate # for your mirror of choice. # #deb http://ftp.debian.org/debian/ jessie-updates main contrib #deb-src http://ftp.debian.org/debian/ jessie-updates main contrib deb http://software.virtualmin.com/vm/6/gpl/apt virtualmin-jessie main deb http://software.virtualmin.com/vm/6/gpl/apt virtualmin-universal main So then I try to install a missing package (and get the same rsponse for every missing package): sudo apt install libauthen-pam-perl Reading package lists... Done Building dependency tree Reading state information... Done Package libauthen-pam-perl is not available, but is referred to by another package. This may mean that the package is missing, has been obsoleted, or is only available from another source E: Package 'libauthen-pam-perl' has no installation candidate So, I try to add the repo that contains apt-show-versions (one of the missing packages): sudo add-apt-repository ... But that command (add-apt-repository) doesn't exist. So I try to load software-properties-common and that package cannot be located either. How do I get out of this insanity and just get something loaded? This is what I get for sudo apt update: Hit http://software.virtualmin.com virtualmin-jessie InRelease Hit http://software.virtualmin.com virtualmin-universal InRelease Hit http://packages.sury.org jessie InRelease Hit http://security.debian.org jessie/updates InRelease Hit http://software.virtualmin.com virtualmin-jessie/main amd64 Packages Hit http://packages.sury.org jessie/main amd64 Packages Get:1 http://packages.sury.org jessie/main Translation-en_GB [169 B] Get:2 http://packages.sury.org jessie/main Translation-en [169 B] Hit http://security.debian.org jessie/updates/main Sources Hit http://security.debian.org jessie/updates/contrib Sources Hit http://security.debian.org jessie/updates/main amd64 Packages Get:3 http://packages.sury.org jessie/main Translation-en_GB [169 B] Hit http://security.debian.org jessie/updates/contrib amd64 Packages Hit http://security.debian.org jessie/updates/contrib Translation-en Hit http://security.debian.org jessie/updates/main Translation-en Get:4 http://packages.sury.org jessie/main Translation-en [169 B] Hit http://software.virtualmin.com virtualmin-universal/main amd64 Packages Get:5 http://packages.sury.org jessie/main Translation-en_GB [169 B] Get:6 http://packages.sury.org jessie/main Translation-en [169 B] Get:7 http://packages.sury.org jessie/main Translation-en_GB [169 B] Get:8 http://packages.sury.org jessie/main Translation-en [169 B] Get:9 http://packages.sury.org jessie/main Translation-en_GB [169 B] Ign http://packages.sury.org jessie/main Translation-en_GB Get:10 http://packages.sury.org jessie/main Translation-en [169 B] Ign http://packages.sury.org jessie/main Translation-en Ign http://software.virtualmin.com virtualmin-jessie/main Translation-en_GB Ign http://software.virtualmin.com virtualmin-jessie/main Translation-en Ign http://software.virtualmin.com virtualmin-universal/main Translation-en_GB Ign http://software.virtualmin.com virtualmin-universal/main Translation-en