Did the sudo apt update and tried again - same results.
Ran this command:
Output:
dbrokaw@DRBL14:~$ cat /etc/apt/sources.list etc/apt/sources.list.d/*
deb http://repo.pureos.net/pureos/ byzantium main
deb http://repo.pureos.net/pureos/ byzantium-security main
deb http://repo.pureos.net/pureos/ byzantium-updates main
cat: ‘etc/apt/sources.list.d/*’: No such file or directory