After upgrade, error "print service is not available"

Hello, after upgrading my iMac to macOS Sierra, I started to get "print service is not available" errors on startup.

I have two printers that I'm connected to. When I log into my computer, both printers will appear in my dock with a pop-up window showing an error window saying "print service is not available". I can click ok and continue to use the printers with no other issues arising.

Any idea what's going on? Thanks!