When u add a datafile in Primary then those changes are not immediately propagated to standby. Once Log with this changes applied to standby, standby database create a filename in $ORACLE_HOME/dbs. This is just a file name and does not have physical file. After this even all log apply service will fail as this is an unknown file for oracle. So You need to apply following command for creaating approprote file on your syandby server.
alter database create datafile ‘/oracle/app/oracle/product/10.1/dbs/UNNAMED00012’ as ‘/uocdb5/oradata/CIF/CIF_TEMP_TPF_LOAD_002.dbf’;