OK, after doing some internet search and asking AI here's where I am at:
cat /etc/apt/sources.list
deb Index of /ubuntu focal main restricted universe multiverse
deb Index of /ubuntu focal-updates main restricted universe multiverse
deb-src Index of /ubuntu focal-updates main restricted universe multiverse
deb Index of /ubuntu focal-security main restricted universe multiverse
deb-src Index of /ubuntu focal-security main restricted universe multiverse
deb Index of /ubuntu focal-backports main restricted universe multiverse
deb-src Index of /ubuntu focal-backports main restricted universe multiverse
deb Index of /ubuntu focal partner
deb-src Index of /ubuntu focal partner
ls /etc/apt/sources.list.d
zorin.list zorinos-ubuntu-drivers-focal.list zorinos-ubuntu-stable-focal.list
zorin.list.save zorinos-ubuntu-drivers-focal.list.save zorinos-ubuntu-stable-focal.list.save
zorinos-ubuntu-apps-focal.list zorinos-ubuntu-patches-focal.list
zorinos-ubuntu-apps-focal.list.save zorinos-ubuntu-patches-focal.list.save
sudo apt update && sudo apt upgrade
Hit:1 Index of /ubuntu focal InRelease
Hit:2 http://archive.ubuntu.com/ubuntu focal InRelease
Hit:3 http://archive.ubuntu.com/ubuntu focal-updates InRelease
Hit:4 http://archive.ubuntu.com/ubuntu focal-security InRelease
Hit:5 http://archive.ubuntu.com/ubuntu focal-backports InRelease
Reading package lists... Done
Building dependency tree
Reading state information... Done
All packages are up to date.
Reading package lists... Done
Building dependency tree
Reading state information... Done
Calculating upgrade... Done
The following security updates require Ubuntu Pro with 'esm-infra' enabled:
libsoup-gnome2.4-1 linux-headers-generic-hwe-20.04 libopenjp2-7
bind9-dnsutils poppler-utils gstreamer1.0-alsa libcups2 intel-microcode
gnupg-utils xserver-common gir1.2-soup-2.4 gpg-wks-client
gstreamer1.0-plugins-base-apps openssl libblockdev-swap2 xserver-xorg-core
gir1.2-gdkpixbuf-2.0 libnvidia-compute-535 libnvidia-compute-535 gnupg-l10n
libgdk-pixbuf2.0-0 libssh-4 linux-modules-nvidia-510-generic-hwe-20.04
libpython3.8-minimal libctf-nobfd0 libwbclient0 libnvidia-encode-535
libnvidia-encode-535 libsystemd0 nvidia-kernel-common-535 gcc-10-base
gcc-10-base libavahi-glib1 gstreamer1.0-plugins-good libgs9
xserver-xorg-video-nvidia-535 libnvidia-gl-535 libsqlite3-0 python3-protobuf
python3-urllib3 binutils libnvidia-fbc1-535 libnvidia-fbc1-535 libsnmp-base
bind9-host libitm1 libnvidia-decode-535 libnvidia-decode-535
libavahi-common-data libavahi-common3 sudo gpg-wks-server libpython3.8
python3.8 xserver-xorg-legacy gpg libblockdev-crypto2 udev
gstreamer1.0-plugins-base cups-server-common libnvidia-cfg1-535
libblockdev-loop2 libquadmath0 libklibc libblockdev-fs2 cups-common
linux-image-generic-hwe-20.04 libblockdev-part2 nvidia-utils-535
python3-requests libgstreamer-plugins-good1.0-0 libudev1 libsoup2.4-1
gstreamer1.0-pulseaudio systemd-timesyncd dirmngr libavahi-ui-gtk3-0
linux-generic-hwe-20.04 samba-libs binutils-x86-64-linux-gnu xserver-xephyr
gstreamer1.0-gtk3 cups-filters linux-modules-nvidia-535-generic-hwe-20.04
libtiff5 udisks2 libsnmp35 libtsan0 libubsan1 cups-ppdc libcaca0
libprotobuf-lite17 avahi-daemon libgfortran5 libcupsfilters1
python3.8-minimal libgstreamer-gl1.0-0 systemd-sysv libblockdev2
nvidia-compute-utils-535 libavahi-core7 gpgv libpam-systemd
libgstreamer-plugins-base1.0-0 xwayland gstreamer1.0-x ghostscript liblsan0
systemd libgomp1 libgdk-pixbuf2.0-bin nvidia-driver-535 libfontembed1
libssh-gcrypt-4 gir1.2-gst-plugins-base-1.0 libblockdev-utils2 ghostscript-x
libgdk-pixbuf2.0-common libsmbclient libmysqlclient21 libnss-systemd
libgs9-common avahi-autoipd binutils-common libblockdev-part-err2 libgcc-s1
libgcc-s1 cups-filters-core-drivers libxml2 libbinutils libpython3.8-stdlib
libgnutls30 libudisks2-0 cups-bsd avahi-utils cups-core-drivers libatomic1
libatomic1 libpoppler-cpp0v5 cups-daemon libssl1.1 libnvidia-common-535
gnupg libcc1-0 libprotobuf17 libcupsimage2 libpoppler-glib8 libstdc++6
libstdc++6 libpoppler97 libavahi-client3 cups cups-client cups-ipp-utils
klibc-utils libnvidia-extra-535 gpg-agent bind9-libs gpgconf gstreamer1.0-gl
libctf0 cups-browsed libxslt1.1 gpgsm nvidia-kernel-source-535 libpng16-16
Learn more about Ubuntu Pro at Ubuntu Pro | Ubuntu
0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
Initially I suspected I was missing sources so I found this on the web:
Ubuntu 20.04 LTS (Focal Fossa) -- Full sources.list
deb Index of /ubuntu focal main restricted universe multiverse
deb-src Index of /ubuntu focal main restricted universe multiverse
deb Index of /ubuntu focal-updates main restricted universe multiverse
deb-src Index of /ubuntu focal-updates main restricted universe multiverse
deb Index of /ubuntu focal-security main restricted universe multiverse
deb-src Index of /ubuntu focal-security main restricted universe multiverse
deb Index of /ubuntu focal-backports main restricted universe multiverse
deb-src Index of /ubuntu focal-backports main restricted universe multiverse
deb Index of /ubuntu focal partner
deb-src Index of /ubuntu focal partner
After doing some Terminal commands in an effort to update/install/clean/purge/etc. Which resulted in some updating. I see now that:
deb-src Index of /ubuntu focal main restricted universe multiverse is no longer listed as source. Also "The following security updates require Ubuntu Pro with 'esm-infra' enabled:" and all the text after it is new.
I still get this error:
[CHECKING] Started
[CHECKING:Validating Upgrade Attempt] Started
[CHECKING:Validating Upgrade Attempt] Completed
[CHECKING:Checking Filesystem] Started
[CHECKING:Checking Filesystem] Completed
[CHECKING:Creating Necessary Files] Started
[CHECKING:Creating Necessary Files] Completed
[CHECKING:Adding GPG Keys] Started
[CHECKING:Adding GPG Keys] Completed
[CHECKING:Restarting Apt] Started
[CHECKING:Restarting Apt] Completed
[CHECKING:Simulating Flatpak Transaction] Started
[CHECKING:Simulating Flatpak Transaction] Completed
[CHECKING:Processing Apt Repos] Started
[CHECKING:Processing Apt Repos] Completed
[CHECKING:Updating Apt Repos] Started
[CHECKING:Updating Apt Repos] Completed
[CHECKING:Calculating Upgradeable Packages] Started
[CHECKING:Calculating Upgradeable Packages] Completed
[CHECKING:Simulating Apt Transaction] Started
[CHECKING:Simulating Apt Transaction] Fatal Error: { GDBus.Error:org.debian.apt.TransactionFailed: error-no-package: Package zorin-os-16-to-17-upgrade isn't available }
[CHECKING:Simulating Apt Transaction] Failed
[CHECKING] Failed
[CHECKING:Restoring System] Started
[CHECKING:Restoring System] Completed