After installation, 'Oracle User Wizard' runs and user connects using SYSTEM as the user. This error then shows.
"ORA-01031: insufficient privileges"
SYSTEM is one of the default oracle user other than SYS, created with the creation of the database and this doesn’t have SYSDBA privilege. Although it has much power - as it is granted the DBA role, is still ordinary user.
Do not use any system accounts. We recommend creating a separate user for Spotlight or using a personal account with SYSDBA privilege.
Refer to 'Getting Started Guide' for more information.