Following errors comes up when selecting 'Start trace for these sessions' in the Session Browser:
ORA-06550: line 1, column 7:
PLS-00201: identifier 'SYS.DBMS_SYSTEM' must be declared
ORA-06550: line 1, column 7:
PL/SQL: Statement ignored
The SYS.DBMS_SYSTEM.set_sql_trace_in_session package is invalid or the current user does not have the Oracle privileges to access the package.
RESOLUTION 1:
Have the DBA login as SYS and grant Execute on the SYS.DBMS_SYSTEM package to the user/schema doing the trace.
RESOLUTION 2:
Recompile the 'sys.dbms_system.set_sql_trace_in_session' package so that it is valid.
Note: permissions are required to do this, and access to SYS user is needed to recompile SYS packages.