This typically means that either there is no Alco-Sensor IV instrument set up and properly configured, or the calibration standard has not been properly entered, including lot number, expected value, and expiration date. Configuration problems with the printer will not cause this particular error message. Try first to verify the configuation of your intrument and your standard. This can be done in the configuration menu, accessable by clicking "Configure" from the main menu. Instruments are configured from the INSTRUMENT tab, and Standards are configured from the SETTINGS tab, and then by selecting CAL STANDARD.