ORACLE: SYS, system login failure problem: ORA-01031: insufficient privileges

Enter the User name: SYS/sys as sysdba
Error:
ORA-01031: insufficient privileges

 

Enter the User name: System/system as sysoper
Error:
ORA-01031: insufficient privileges

 

Sys and system users cannot log on, and no permission is displayed:

SQL> conn system/System
Connected.
SQL> grant sysdba to sys
2;
Grant sysdba to sys
*
Error is located in row 1st:
ORA-01031: insufficient Permissions

 

The password file is re-created.

 

View users:

SQL> conn system/System
Connected.
SQL> select * from V $ pwfile_users;

Unselected row

 

Finally, check the sqlnet. ora file under D:/Oracle/ora92/Network/admin and find that the file does not exist.

After copying a file, you can log on normally:

SQL> Conn/As sysdba
Connected.
SQL>