This shows the following query for the SYSTEM account:

select * from oudm_sys.dwb_acct_bal_hist;

The output shows:

ORA-01031 insufficient privileges

At this stage, SYSTEM cannot select from the OUDM_SYS.DWB_ACCT_BAL_HIST table because it is protected with Oracle Database Vault. The SYSTEM account normally has access to all objects in the OUDM schema, but now that you have safeguarded the DWB_ACCT_BAL_HIST table with Oracle Database Vault, this is no longer the case.