There are various reasons for Canon printer offline issue. A malfunctioning internet connection or the printer can be in sleep mode. The printer has broken down. A problem with paper jamming exists. The paper tray was empty. Alternatively, your internet connection is quite sluggish or a slack USB cable or a wire. An infection caused by a virus or malware. Printer drivers and software have been corrupted. Printer drivers no longer support the current Windows after an upgrade.