Oracle Message ORA-08429 - raw data has invalid digit in display type data

ERRORraw data has invalid digit in display type data
CAUSEThe input raw buffer passed to a UTL_PG RAW_TO_NUMBER conversion routine contained invalid data. The picture mask parameter specified a digit, but the corresponding input from the raw data did not contain a valid digit.
ACTIONEither the input data is incorrect, or the picture mask is incorrect. Correct the appropriate item.