You should not be alarmed if your printer has abruptly shut down, displaying the Canon printer offline error. You may use a few troubleshooting approaches to try to address the issue on your own. See to it that the printer and router are both connected through the Ethernet cable. Perform a configuration audit of your network. Ascertain that both the printer and the computer are connected properly through USB cables. Conduct a visual inspection and ensure that the power cables are firmly connected to the power socket.