"Cannot find main operator description file OperatorsCore.xml"

Hi, I am a newbie to RapidMiner, and trying execute simple Java app.
I want to import "operators.xml" which I generated before but I get the followin error:
SEVERE: Cannot find main operator description file com/rapidminer/resources/ OperatorsCore.xml.
my source code is as follows: 

import com.rapidminer.RapidMiner;
import com.rapidminer.RapidMiner.ExecutionMode;
import com.rapidminer.RepositoryProcessLocation;
import com.rapidminer.operator.IOContainer;
import com.rapidminer.operator.IOObject;
import com.rapidminer.operator.Operator;
import com.rapidminer.repository.Entry;
import com.rapidminer.repository.ProcessEntry;
import com.rapidminer.repository.RepositoryLocation;
import com.rapidminer.Process;
import com.rapidminer.tools.OperatorService;

public class DBReader {

RepositoryLocation location;

public DBReader() {
System.setProperty("rapidminer.init.operators",".../operatros");
System.setProperty("rapidminer.home",".../rapidminer");
System.setProperty(RapidMiner.PROPERTY_RAPIDMINER_INIT_OPERATORS, ".../OperatorsCore.xml");
RapidMiner.setExecutionMode(RapidMiner.ExecutionMode.EMBEDDED_WITH_UI);
RapidMiner.init();
Process process = new Process();
try {
location = new RepositoryLocation(".../operatros");
Entry entry = location.locateEntry();
System.out.println(OperatorService.getOperatorDescription("read_database").getName());
    Operator inputOperator = OperatorService.createOperator("Read Database");

}
catch(Exception e) {
}
}

public static void main(String[] args) {
new DBReader();
}

}

Can you please help me.