ORA-01031 insufficient privileges

2 possible reasons

• check password file, if possible, recreate them on all nodes to make them consistent
• double check password file name ,must be orapw<SID> , not orapwd<SID>
• When we setup dataguard service, the standby DB may need to copy password file from primary, and rename as  orapw<sid>
• Use below sql to check password file user

  select * from v$pwfile_users;
  select value from v$option where parameter='Oracle Database Vault';