The program crash upon registration

When testing the app
After entering the username, email and password then clicking Sign Up Button the program crash and stop working

package com.example.ashraf.gocenetr;


import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
import android.widget.Toast;


import com.backendless.Backendless;
import com.backendless.BackendlessUser;
import com.backendless.exceptions.BackendlessFault;
import com.backendless.async.callback.AsyncCallback;


public class RegisterActivity extends AppCompatActivity {


    private static final String APP_ID = "D8D37700-A4B8-782A-FFEC-99244E147500";
    private static final String SECRET_KEY = "6CD85EE3-669F-CDE8-FF38-F821A763BF00";
    private static final String VERSION = "v1";


    private TextView mUserNameRegister;
    private TextView mEmailRegister;
    private TextView mPasswordRegister;
    private Button mUserNameSignUpButton;




    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_register);


        Backendless.initApp(RegisterActivity.this, APP_ID, SECRET_KEY, VERSION);


        mUserNameRegister = (TextView) findViewById(R.id.userNameRegister);
        mEmailRegister = (TextView) findViewById(R.id.eMailRegister);
        mPasswordRegister = (TextView) findViewById(R.id.passwordRegister);
        mUserNameSignUpButton = (Button) findViewById(R.id.SignUp);


        mUserNameSignUpButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v)
            {


                String username = mUserNameRegister.getText().toString();
                String email = mEmailRegister.getText().toString();
                String password = mPasswordRegister.getText().toString();


                BackendlessUser user = new BackendlessUser();


                user.setProperty( "name", username );
                user.setProperty( "email", email );
                user.setPassword(password);


                Backendless.UserService.register( user, new AsyncCallback<BackendlessUser>()
                {
                    public void handleResponse( BackendlessUser registeredUser )
                    {
                        Toast.makeText(RegisterActivity.this, "You registered successfully.", Toast.LENGTH_SHORT).show();
                    }


                    public void handleFault( BackendlessFault fault )
                    {
                        Toast.makeText(RegisterActivity.this, "You registered unsuccessfully.", Toast.LENGTH_SHORT).show();
                    }
                } );
            }
        });








    }
}

And this is the xml file too

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context="com.example.ashraf.gocenetr.RegisterActivity">


    <EditText
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:id="@+id/userNameRegister"
        android:hint="User Name"
        android:layout_alignParentTop="true"
        android:layout_alignParentLeft="true"
        android:layout_alignParentStart="true" />


    <EditText
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:id="@+id/eMailRegister"
        android:hint="E-Mail"
        android:layout_below="@+id/userNameRegister"
        android:layout_alignParentLeft="true"
        android:layout_alignParentStart="true" />


    <EditText
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:id="@+id/passwordRegister"
        android:hint="Password"
        android:layout_below="@+id/eMailRegister"
        android:layout_alignParentLeft="true"
        android:layout_alignParentStart="true" />


    <Button
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="Sign Up"
        android:id="@+id/SignUp"
        android:layout_below="@+id/passwordRegister"
        android:layout_alignParentLeft="true"
        android:layout_alignParentStart="true" />
&lt;/RelativeLayout&gt;

And here is the manifest file too

&lt;?xml version=&quot;1.0&quot; encoding=&quot;utf-8&quot;?&gt;
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.ashraf.gocenetr">
    &lt;uses-permission android:name=&quot;android.permission.ACCESS_NETWORK_STATE&quot;/&gt;
    &lt;uses-permission android:name=&quot;android.permission.INTERNET&quot;/&gt;


    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:supportsRtl="true"
        android:theme="@style/AppTheme">
        <activity android:name=".RegisterActivity">
            &lt;intent-filter&gt;
                <action android:name="android.intent.action.MAIN" />


                &lt;category android:name=&quot;android.intent.category.LAUNCHER&quot; /&gt;
            &lt;/intent-filter&gt;
        </activity>
    </application>


&lt;/manifest&gt;

you should see some errors in the android studio log
also you can use code generation to see how to register and login users http://take.ms/WW5rg