The Line Sensor of the printer is not functioning correctly. Either the Line Sensor shutter has failed to open, there is a failure to communicate with the Line Sensor, the Line Sensor is not calibrated correctly, or the firmware is not compatible with the Line Sensor.
Try the following:
1. Switch the Power OFF from the back of the Printer and disconnect the power cord. Reconnect the power cord and power On the Printer.
2. Perform the Line Sensor calibration.
3. Check that the Printer has the latest Firmware version. If not, update the Firmware to the latest version.
4. Perform the Carriage Test to troubleshoot the problem further.
5. If the System Error continues, replace the Line Sensor.