Why does the message INVALID INK CRTG appear on my product's LCD?

• This message appears if you replace a Photo Black ink cartridge with a Matte Black ink cartridge, or vice versa, without using the Black Ink Conversion Kit. To switch between the two types of black ink, you must use the Black Ink Conversion Kit (included with the printer) and run the Black Ink Change from the user control panel. See Changing the Black Ink Cartridge.