title: Sql plus doesn't show English
body: <p>SQL plus doesn't show English as shown here</p>
  
  <p><img src="https://i.stack.imgur.com/anqDV.png" alt="sql plus"> </p>
  
  <p>and it also returns error for system user name and password, even the user name and password are correct!
  The error is  ORA-12560:TNS:protocol adapter error, what should I dخ??</p>