Oracle Message ORA-08456 - no sign in picture mask but SIGN clause in mask options

ERRORno sign in picture mask but SIGN clause in mask options
CAUSEThe picture mask parameter passed to a UTL_PG conversion routine contained no sign symbol (S, +, or -), but the mask options parameter contained a SIGN clause. A sign symbol is required in the picture mask parameter when the mask options parameter contains a SIGN clause.
ACTIONCorrect the picture mask parameter or the mask options parameter.