ORA-00265: instance recovery required, cannot set ARCHIVELOG mode

Error description:

SQL> alter database archivelog;
alter database archivelog
*
ERROR at line 1:
ORA-00265: instance recovery required, cannot set ARCHIVELOG mode

Cause:

The database was crashed itself or you issued shutdown abort or startup force commands.

In my case I issued the following command, to take database into mount state.

SQL> startup mount force;

Solution:

SQL> select status from v$instance;

STATUS
————————————
MOUNTED

SQL> alter database open;

Database altered.

SQL> shutdown immediate;

Database closed.
Database dismounted.
ORACLE instance shut down.

SQL> startup mount;
ORACLE instance started.

Total System Global Area 293601280 bytes
Fixed Size 1248600 bytes
Variable Size 88081064 bytes
Database Buffers 197132288 bytes
Redo Buffers 7139328 bytes
Database mounted.

SQL> alter database archivelog;

Database altered.

SQL> alter database open;

Database altered.