Printer Add button not enabled

Solution 1:

Try to open a terminal (or alt-f2 to display command execution prompt) and run

sudo system-config-printer

and check if you can add a printer from there.

Solution 2:

Open a web browser and navigate to http://localhost:631. This is the real interface to your printing system. If you want to do anything fancy, do it here. You are eliminating a lot of potential error stemming from bugs and flaws in the gnome printer dialog. Mostly the gnome dialog is just oversimplifying on some advanced functions.

If you don't see a website on localhost:631 your cups daemon (the printing system) is not running at all. Make sure it is installed.

Solution 3:

sudo apt-get install cups

#my CUPS was not installed after upgrading to 18.04, after i did this printers showed right up just had to close and reopen the printer app