I have received a reply from Oracle and here it is, just wanted to share with u all

Hi,

this is because of auditing with binds in either Standard Auditing
(audit_trail = DB_EXTERNAL) or Fine Grained Auditing with
audit_trail => DBMS_FGA.DB_EXTENDED, the 'kzabndinf' is an internal
module that is supposed to translate the bind values to a readable
string, the problem is it does not support all datatypes,
datatype 121 is 'DTYADT' which is some sort of object type.
In that case it writes this message to a trace file.

This is expected behavior, it's not a bug. It's likely that in future
releases we'll enhance the auditing system to be able to capture
binds of any type.

greetings,

Harm ten Napel