The machine needs maintenance.

Once this message appears, it is recommended to take your machine to an authorized dealer or nearest authorized service center for a regular maintenance check.
Although this message will disappear and the machine will continue to function once you touch "OK" key, the message will display several more times until the appropriate maintenance is performed.
Please take the time to arrange the maintenance your machine requires once this message appears.
Such steps will help to ensure you receive continued, uninterrupted hours of machine operation for the future.