ORA-19573: cannot obtain exclusive enqueue for datafile 1 RM

Received below error while doing the dataguard restoration on standby database.

RMAN-03002: failure of restore command at 06/30/2019 13:23:19

ORA-19870: error while restoring backup piece /data/rman/CDB/CDB1_D_20190607_0au 3g8ip_s10_p1

ORA-19573: cannot obtain exclusive enqueue for datafile 1

Follow the below steps to solve this error message.

Shutdown the database.

RMAN> shutdown immediate;

database closed

database dismounted

Oracle instance shut down

Start the database in mount stage.

RMAN> startup mount

Restore the database

RMAN> restore database;