How do i make use of two relative layouts on one single screen?

I cant operate with two relative layouts (one in another). my app doesn't starts. it keeps stopping. I am using a physical device (Samsung Galaxy On Max) for running my apps from android studio.

XML file:

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">

    <Button
        android:id="@+id/Next"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginStart="161dp"
        android:layout_marginTop="340dp"
        android:layout_marginEnd="162dp"
        android:onClick="Next"
        android:text="Next"
        android:visibility="visible"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

    <androidx.constraintlayout.widget.ConstraintLayout
        android:id="@+id/newLayout"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:visibility="invisible">

        <TextView
            android:id="@+id/nextText"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginStart="132dp"
            android:layout_marginTop="354dp"
            android:layout_marginEnd="132dp"
            android:background="#F30808"
            android:text="There you Go!"
            android:textColor="#0B0A0A"
            android:textSize="24sp"
            android:visibility="visible"
            app:layout_constraintEnd_toEndOf="parent"
            app:layout_constraintStart_toStartOf="parent"
            app:layout_constraintTop_toTopOf="parent" />
    </androidx.constraintlayout.widget.ConstraintLayout>

</androidx.constraintlayout.widget.ConstraintLayout>

Java file:

package com.example.twolayouts;

import androidx.appcompat.app.AppCompatActivity;

import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.RelativeLayout;
import android.widget.TextView;

public class MainActivity extends AppCompatActivity {
    TextView nextText;
    Button Next;
    RelativeLayout newLayout;

    public void Next(View view)
    {
        Next.setVisibility(View.INVISIBLE);
        newLayout.setVisibility(View.VISIBLE);
    }

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        nextText=(TextView)findViewById(R.id.nextText);
        Next=(Button)findViewById(R.id.Next);
        newLayout=(RelativeLayout)findViewById(R.id.newLayout);
    }
}

Why you are creating object of relative layout while your layout in xml is constraint layout.

Try this :

public class MainActivity extends AppCompatActivity {
TextView nextText;
Button Next;
ConstraintLayout newLayout;

public void Next(View view)
{
    Next.setVisibility(View.INVISIBLE);
    newLayout.setVisibility(View.VISIBLE);
}

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    nextText=(TextView)findViewById(R.id.nextText);
    Next=(Button)findViewById(R.id.Next);
    newLayout=(ConstraintLayout)findViewById(R.id.newLayout);
}
}

You should try looking into your logcat windows it will help you out for what error you are facing.

Kindly check on which line of code the app is crashing. Post your error log here !

problem is you used constraint layout in your xml layout file and creating object of relative layout in java file

replace below line :

RelativeLayout newLayout;

with :

ConstraintLayout newLayout;