ORA-29549: class SOME.SYSTEM CLASS has changed, Java session state cleared

Moving from the Java development community:

Hi

We're encountering the error in the Subject for the first time in our mature client-server application where user behaviour and environmental load at least is becoming more intense in some complex regard.

No App Server.

There is a networked Java app which uses Java DB, called from a bat file that connects to Oracle through JDBC

The error is being written to an application database log table along with references to PL/SQL lines, which are in similar areas of functionality.

I propose to

SQL> alter system set events '29549 TRACE NAME ERRORSTACK LEVEL 3';