This kind of errors must be reported to MOS.
HTH - Antonio NAVARRO.
If this is XE, Oracle support will not support it.
What else you see in xe_ora_4546.trc file. What are you trying to do when you get this error? is it crashing on some query?
this ORA 600 with the first argument you posted is a bug but different bug for different versions. Post some more details so people can help you.