My activity got crashed when I run my application in kotlin

Question

I am creating one learning application in which one activity suddenly crashed. everything I did for it, I install application again but not get succussed. Please suggest me any solutions

In this is activity I join variable activity (Variable is name of activity)

package com.example.myapplication.java

import android.annotation.SuppressLint
import android.app.ActivityOptions
import android.content.Intent
import androidx.appcompat.app.AppCompatActivity
import android.os.Bundle
import android.widget.Button
import android.widget.ImageView
import com.example.myapplication.R
import com.example.myapplication.java.Variable

class Java_Basic : AppCompatActivity() {
    @SuppressLint("MissingInflatedId")
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_java_basic)

        val back: ImageView = findViewById(R.id.back)
        val variable: Button = findViewById(R.id.variable_btn)

        back.setOnClickListener {
            onBackPressedDispatcher.onBackPressed()
        }

        variable.setOnClickListener{
            intent = Intent(this,  Variable::class.java)
            startActivity(intent, ActivityOptions.makeSceneTransitionAnimation(this).toBundle())
        }
    }
}

This is Variable activity

package com.example.myapplication.java

import android.annotation.SuppressLint
import androidx.appcompat.app.AppCompatActivity
import android.os.Bundle
import android.widget.ImageView
import com.example.myapplication.R

class Variable : AppCompatActivity() {
    @SuppressLint("MissingInflatedId")
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_variable)

        val back: ImageView = findViewById(R.id.back2)

        back.setOnClickListener {
            onBackPressedDispatcher.onBackPressed()
        }
    }
}

this is Variable.xml

<?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"
    android:background="@drawable/bg_main" >

    <ImageView
        android:id="@+id/back2"
        android:layout_width="30dp"
        android:layout_height="30dp"
        android:layout_marginStart="16dp"
        android:layout_marginTop="40dp"
        android:src="@drawable/ic_baseline_arrow_back_242"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        tools:ignore="ContentDescription" />

    <ImageView
        android:id="@+id/imageView"
        android:layout_width="49dp"
        android:layout_height="49dp"
        android:layout_marginStart="84dp"
        android:layout_marginTop="28dp"
        android:src="@drawable/javalogo"
        app:layout_constraintStart_toEndOf="@+id/back2"
        app:layout_constraintTop_toTopOf="parent"
        tools:ignore="ContentDescription" />

    <TextView
        android:id="@+id/java"
        android:layout_width="79dp"
        android:layout_height="41dp"
        android:layout_marginTop="36dp"
        android:layout_marginEnd="104dp"
        android:fontFamily="@font/el_messiri_medium"
        android:gravity="center"
        android:text="Java"
        android:textAlignment="center"
        android:textColor="@color/black"
        android:textSize="35sp"
        android:textStyle="bold"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintHorizontal_bias="0.0"
        app:layout_constraintStart_toEndOf="@+id/imageView"
        app:layout_constraintTop_toTopOf="parent"
        tools:ignore="HardcodedText" />

    <ScrollView
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_marginTop="88dp"
        android:orientation="vertical"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintHorizontal_bias="0.0"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        tools:ignore="MissingConstraints">

        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:orientation="vertical">
            <androidx.cardview.widget.CardView
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:layout_gravity="center_horizontal"
                android:padding="10dp"
                android:layout_margin="10sp"
                app:cardBackgroundColor="#36393F"
                app:cardCornerRadius="10dp"
                app:cardElevation="8dp">

                <TextView
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:layout_marginStart="10sp"
                    android:layout_marginTop="10sp"
                    android:fontFamily="@font/el_messiri_medium"
                    android:text="@string/variable"
                    android:layout_gravity="center_horizontal"
                    android:textColor="@color/white"
                    android:textSize="24sp"
                    android:textStyle="bold" />

                <TextView
                    android:id="@+id/intro"
                    android:layout_width="match_parent"
                    android:layout_height="wrap_content"
                    android:layout_marginTop="55dp"
                    android:layout_marginBottom="10sp"
                    android:autoLink="web"
                    android:fontFamily="@font/alata"
                    android:lineHeight="27dp"
                    android:justificationMode="inter_word"
                    tools:ignore="UnusedAttribute"
                    android:paddingHorizontal="10dp"
                    android:text="@string/variable_intro"
                    android:textColor="@color/white"
                    android:textColorLink="#9997CB"
                    android:textSize="16sp" />
            </androidx.cardview.widget.CardView>

            <androidx.cardview.widget.CardView
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_gravity="center_horizontal"
            android:padding="10dp"
            android:layout_margin="10sp"
            app:cardBackgroundColor="#36393F"
            app:cardCornerRadius="10dp"
            app:cardElevation="8dp">
                <LinearLayout
                    android:layout_width="match_parent"
                    android:layout_height="wrap_content"
                    android:orientation="vertical">
                    <TextView
                        android:layout_width="wrap_content"
                        android:layout_height="wrap_content"
                        android:layout_marginStart="10dp"
                        android:layout_marginTop="10dp"
                        android:fontFamily="@font/el_messiri_medium"
                        android:text="@string/local_var"
                        android:layout_gravity="center_horizontal"
                        android:textColor="@color/white"
                        android:textSize="24sp"
                        android:textStyle="bold" />

                    <TextView
                        android:layout_width="match_parent"
                        android:layout_height="wrap_content"
                        android:layout_marginTop="10dp"
                        android:layout_marginBottom="10sp"
                        android:autoLink="web"
                        android:fontFamily="@font/alata"
                        android:lineHeight="27dp"
                        android:justificationMode="inter_word"
                        tools:ignore="UnusedAttribute"
                        android:paddingHorizontal="10dp"
                        android:text="@string/localvar_explain"
                        android:textColor="@color/white"
                        android:textColorLink="#9997CB"
                        android:textSize="16sp" />

                </LinearLayout>
            </androidx.cardview.widget.CardView>

            <androidx.cardview.widget.CardView
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:layout_gravity="center_horizontal"
                android:padding="10dp"
                android:layout_margin="10sp"
                app:cardBackgroundColor="#36393F"
                app:cardCornerRadius="10dp"
                app:cardElevation="8dp">
                <LinearLayout
                    android:layout_width="match_parent"
                    android:layout_height="match_parent"
                    android:orientation="vertical">
                    <TextView
                        android:id="@+id/sample"
                        android:layout_width="match_parent"
                        android:layout_height="wrap_content"
                        android:layout_marginTop="10sp"
                        android:layout_marginBottom="10sp"
                        android:autoLink="web"
                        android:fontFamily="@font/alata"
                        android:lineHeight="27sp"
                        android:paddingHorizontal="10dp"
                        android:text="@string/java_sample"
                        android:textColor="@color/white"
                        android:textColorLink="#9997CB"
                        android:textSize="16sp"
                        tools:ignore="UnusedAttribute" />

                    <androidx.cardview.widget.CardView
                        android:layout_width="335sp"
                        android:layout_height="wrap_content"
                        android:layout_gravity="center_horizontal"
                        android:padding="10dp"
                        android:layout_margin="15sp"
                        app:cardBackgroundColor="#FFF"
                        app:cardElevation="8dp">

                        <TextView
                            android:id="@+id/code1"
                            android:layout_width="match_parent"
                            android:layout_height="wrap_content"
                            android:layout_marginTop="10sp"
                            android:layout_marginBottom="10sp"
                            android:textSize="13sp"
                            android:fontFamily="serif-monospace"
                            android:lineHeight="27sp"
                            android:paddingHorizontal="10dp"
                            android:text="@string/localvar_code"
                            android:textStyle="bold"
                            android:textColor="@color/black"
                            android:textColorLink="#9997CB"
                            android:textIsSelectable="true"
                            tools:ignore="UnusedAttribute" />

                    </androidx.cardview.widget.CardView>
                </LinearLayout>
            </androidx.cardview.widget.CardView>
        </LinearLayout>
    </ScrollView>


</androidx.constraintlayout.widget.ConstraintLayout>