Re-running the catupgrd.sql script caused many ORA-00001 errors similar to below:
ORA-00001: unique constraint (SYS.I_SYSTEM_PRIVILEGE_MAP) violated
ORA-00001: unique constraint (SYS.I_SYSTEM_PRIVILEGE_MAP) violated
ORA-00001: unique constraint (SYS.I_SYSTEM_PRIVILEGE_MAP) violated
ORA-00001: unique constraint (SYS.I_SYSTEM_PRIVILEGE_MAP) violated
ORA-00001: unique constraint (SYS.I_SYSTEM_PRIVILEGE_MAP) violated
ORA-00001: unique constraint (SYS.I_TABLE_PRIVILEGE_MAP) violated
ORA-00001: unique constraint (SYS.I_TABLE_PRIVILEGE_MAP) violated
ORA-00001: unique constraint (SYS.I_STMT_AUDIT_OPTION_MAP) violated
ORA-00001: unique constraint (SYS.I_STMT_AUDIT_OPTION_MAP) violated
ORA-00001: unique constraint (SYS.I_STMT_AUDIT_OPTION_MAP) violated
Bug 8834797 APPSST GSI 11G UNIQUE CONSTRAINT VIOLATED WHILE RUNNING CATUPGRD
Unique constraint errors are expected and acceptable on re-run of catupgrd.sql or utlu111s.sql. These ORA-1 errors can be safely ignored and should not impact the upgrade process in anyway.
If still having issues with DBMS_SESSION then request run dbmsutil.sql prvtutil.plb SYS