According to the info about your system which got added to your bug report no suitable drivers were found for your two printers:
PpdFiles: Canon-MG2900-series: Generic text-only printer EPSON-Epson-Stylus-SX420W: Epson Stylus Scan 2500 Foomatic/stcolor
This gives the impression that there is no Linux support for them.
Did they work with another Linux distribution or an older version of Ubuntu?
According to the info about your system which got added to your bug report no suitable drivers were found for your two printers:
PpdFiles: MG2900- series: Generic text-only printer Epson-Stylus- SX420W: Epson Stylus Scan 2500 Foomatic/stcolor
Canon-
EPSON-
This gives the impression that there is no Linux support for them.
Did they work with another Linux distribution or an older version of Ubuntu?