ORA-38856: CANNOT MARK INSTANCE UNNAMED_INSTANCE_2 (REDO THREAD 2) AS ENABLED

Backup was taken in RAC Database and we are trying to restore it in single instance. During making open resetlogs appears error:

SQL> alter database open resetlogs;
alter database open resetlogs
*
ERROR at line 1:
ORA-38856: cannot mark instance UNNAMED_INSTANCE_2 (redo thread 2) as enabled

Details: ORA-38856: cannot mark instance UNNAMED_INSTANCE_2 (redo thread 2) as enabled. Oracle bug, 4355382 ORA-38856: FAILED TO OPEN DATABASE WITH RESETLOGS WHEN USING RAC BACKUP. The problem is related to the number of threads used by the source database and an expectation that the cloned database must have an identical number of threads. 

Solution: 

 1) Set the following parameter in the auxiliary init.ora file: _no_recovery_through_resetlogs=TRUE. 

 2) Open the database in resetlogs mode. 

 3) Remove _ no_recovery_through_resetlogs=TRUE from init.ora. 

 4) Restart database.