Check the cable connection running from the Canon printer to your computer. If the USB data cable is not completely connected into either the computer or the printer the print request is not going to reach the printer.

Fill the paper tray of the Canon printer. If there is no paper (or only a few sheets) the printer is unable to print the document. Fill the printer tray and retry to print the document.

Open the document you want to print and select the "Print" option. Click the printer selection and choose the Canon printer. If the Canon printer is not selected as the go-to printer it does not receive the printer request.