All Oracle Error CodesOracle DBA Forum

ORA-06559:

wrong datatype requested, string, actual datatype is string
Cause: The sender put different datatype on the pipe than that being requested (package 'dbms_pipe'). The numbers are: 6 - number, 9 - char, 12 - date.
Action: Check that the sender and receiver agree on the number and types of items placed on the pipe.