[12c Switchover]ORA-16475 signalled during: alter database switchover to ...

Environment
12.1.0.2.0  Dataguard

Case switch-over with SQL   mode (12c new commands )

Got below error while verifying switch-over status with 12c new commands
alter database switchover to <DB_UNIQUE_NAME>  verify;

alert log shows 

SWITCHOVER VERIFY: Send VERIFY request to switchover target <DB_UNIQUE_NAME>

SWITCHOVER VERIFY COMPLETE

SWITCHOVER VERIFY WARNING: switchover target temporary files are not the same with the primary. See switchover target's alert log for details.

ORA-16475 signalled during: alter database switchover to <DB_UNIQUE_NAME> verify... 

SWITCHOVER VERIFY BEGIN

SWITCHOVER VERIFY WARNING: primary database has 6 temporary files, this database has 5 temporary files. More temp files  should be added to this database.

SWITCHOVER VERIFY COMPLETE

And added one more tempfile on standby to match the count with existing PRIMARY, retied 

Completed verify with out any warning and continued switch over 

alert log 

SWITCHOVER VERIFY: Send VERIFY request to switchover target <DB_UNIQUE_NAME>

SWITCHOVER VERIFY COMPLETE

Completed: alter database switchover to <DB_UNIQUE_NAME>

From PRIMARY  DB 

alter database switchover to <DB_UNIQUE_NAME>;