Sudo apt install synaptic

[Aravisian]

@Aravisian

sudo sed -i '/\<cdrom:/s/^/#/' /etc/apt/sources.list

Sorry, the Forum Software Alters Code. Needs the right tags.
Just as you see it here:

sudo sed -i '/\<cdrom:/s/^/#/' /etc/apt/sources.list

NOT

sudo sed -i '/<cdrom:/s/^/#/' /etc/apt/sources.list

THIS

sudo sed -i '/\<cdrom:/s/^/#/' /etc/apt/sources.list

@Frog

mike@mike-ROG-Strix-G731GT-G731GT:~$ synaptic

(synaptic:17070): IBUS-WARNING **: 11:39:01.772: Unable to connect to ibus: Could not connect: Connection refused

Synaptic must be opened with Root Privileges:

@Aravisian

Launch synaptic from terminal:

synaptic-pkexec