The specified metered toner cartridge (cyan, magenta, yellow, or black) is installed but the printer does not have metered toner enabled. Replace the metered toner cartridge with a non-metered toner cartridge for that color. To install a toner cartridge, see the installation instructions on the box of the new toner cartridge.
To order a Xerox toner cartridge, contact your local reseller or go to the Phaser® 7760 Supplies and Accessories website.