Press the machine's Black or Color button to dismiss the error. Check the following points, perform Automatic Print Head Alignment again. Make sure that the print head alignment sheet is set in the correct position and orientation on the platen glass. Make sure the platen glass and the print head alignment sheet are not dirty. Make sure the type and size of loaded paper is suitable for Automatic Print Head Alignment. For Automatic Print Head Alignment, always load one sheet of A4 or Letter-sized plain paper. Make sure if print head nozzles are clogged. Print the nozzle check pattern to check the status of the print head. If the error is not resolved, perform Manual Print Head Alignment.