Oracle Message ORA-08443 - syntax error in BLANK WHEN ZERO clause in mask options

ERRORsyntax error in BLANK WHEN ZERO clause in mask options
CAUSEA syntax error was found in the BLANK WHEN ZERO clause in the mask options parameter passed to a UTL_PG conversion routine. Valid specifications are: BLANK ZERO BLANK ZEROS BLANK ZEROES BLANK WHEN ZERO BLANK WHEN ZEROS BLANK WHEN ZEROES
ACTIONCorrect the mask options parameter.