ORA-01665: control file is not a standby control file

Today , After restoring standby database from RMAN backup, got below error 🙁

What is Solution ?

Firstly , I Checked the database_role of STANDBY

sql> SELECT database_role FROM v$database;
 
DATABASE_ROLE
—————-
PRIMARY

After , Primary Database Convert to standby database

sql> Alter database convert to physical standby;

sql> startup mount;
sql> SELECT database_role FROM v$database;
DATABASE_ROLE
—————
PHYSICAL STANDBY

Finally

sql> ALTER DATABASE RECOVER MANAGED STANDBY DATABASE disconnect from session;