For help with the Canon Printer Offline problem on MAC, visit the Apple menu. Select Printer & Scanner under System Preferences as well. Additionally, the left panel will display a pop-up window. To reinstall the printing system, use the right-click menu. You will also need to enter your login name and password. Click OK once you've entered both credentials. There will be a little delay before the printer list appears. The printer can be added the last time by using the + sign.