whenever I try to open the app it keeps stopping. This issue also comes in many other project also.

Here is my MainActivity.kt file

package com.shahid.timerlivedata

import android.annotation.SuppressLint
import android.os.Bundle
import android.widget.TextView
import android.widget.Toast
import androidx.activity.enableEdgeToEdge
import androidx.appcompat.app.AppCompatActivity
import androidx.core.view.ViewCompat
import androidx.core.view.WindowInsetsCompat
import androidx.lifecycle.Observer
import androidx.lifecycle.ViewModelProvider

class MainActivity : AppCompatActivity() {
    @SuppressLint("MissingInflatedId")
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        enableEdgeToEdge()
        setContentView(R.layout.activity_main)
        ViewCompat.setOnApplyWindowInsetsListener(findViewById(R.id.main)) { v, insets ->
            val systemBars = insets.getInsets(WindowInsetsCompat.Type.systemBars())
            v.setPadding(systemBars.left, systemBars.top, systemBars.right, systemBars.bottom)
            insets
        }

        val TxtCount = findViewById<TextView>(R.id.txtCount)
        val edtCount = findViewById<TextView>(R.id.edtCount)
        val btnStart = findViewById<TextView>(R.id.btnStart)
        val btnStop = findViewById<TextView>(R.id.btnStop)

        val mAVieModel = ViewModelProvider(this).get(MainActivityViewModel::class.java)
        mAVieModel.startTimer()

        mAVieModel._seconds.observe(this, Observer{ seconds ->
            TxtCount.text = "$seconds"

        })
        mAVieModel.finished.observe(this, Observer { check ->
            if(check){
                Toast.makeText(this,"Time Completed!!", Toast.LENGTH_LONG).show()
            }

        })

        btnStart.setOnClickListener{
            if(edtCount.text.isEmpty()){
                Toast.makeText(this,"Please Fill the Time", Toast.LENGTH_LONG).show()
            }else{
                mAVieModel.timerValue.value = edtCount.text.toString().toLong()*1000
                mAVieModel.startTimer()
            }
        }
        btnStop.setOnClickListener{
            mAVieModel.stopTimer()
        }
    }
}

Here is my LogCat . I think the Actual Problem is here, but I can’t get it ->

[871] amjc.a(209): VerifyApps: APK Analysis scan failed for com.shahid.timerlivedata (Ask Gemini)
com.google.android.finsky.verifier.apkanalysis.client.ApkAnalysisException: DOWNLOAD_FILE_NOT_FOUND_EXCEPTION while analyzing APK
    at ambw.b(PG:1260)
    at ambw.a(PG:13)
    at bgbs.M(PG:14)
    at bgbs.d(PG:10)
    at algz.b(PG:605)
    at algz.a(PG:222)
    at bfwu.J(PG:40)
    at bfwu.C(PG:12)
    at amjc.a(PG:113)
    at algz.b(PG:632)
    at bfvd.x(PG:6)
    at bgcb.run(PG:111)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1133)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:607)
    at qek.run(PG:1211)
    at java.lang.Thread.run(Thread.java:761)
Package still installed com.shahid.timerlivedata
Late-enabling -Xcheck:jni
Unexpected CPU variant for X86 using defaults: x86
ClassLoader referenced unknown path: /data/app/com.shahid.timerlivedata-1/lib/x86
Background sticky concurrent mark sweep GC freed 21607(876KB) AllocSpace objects, 0(0B) LOS objects, 49% free, 4MB/8MB, paused 6.612ms total 210.244ms
Checking for metadata for AppLocalesMetadataHolderService : Service not found
Before Android 4.1, method android.graphics.PorterDuffColorFilter androidx.vectordrawable.graphics.drawable.VectorDrawableCompat.updateTintFilter(android.graphics.PorterDuffColorFilter, android.content.res.ColorStateList, android.graphics.PorterDuff$Mode) would have incorrectly overridden the package-private method in android.graphics.drawable.Drawable
Shutting down VM
FATAL EXCEPTION: main (Ask Gemini)
Process: com.shahid.timerlivedata, PID: 14609
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.shahid.timerlivedata/com.shahid.timerlivedata.MainActivity}: java.lang.NullPointerException
    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2665)
    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2726)
    at android.app.ActivityThread.-wrap12(ActivityThread.java)
    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1477)
    at android.os.Handler.dispatchMessage(Handler.java:102)
    at android.os.Looper.loop(Looper.java:154)
    at android.app.ActivityThread.main(ActivityThread.java:6119)
    at java.lang.reflect.Method.invoke(Native Method)
    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:886)
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:776)
Caused by: java.lang.NullPointerException
    at com.shahid.timerlivedata.MainActivityViewModel.startTimer(MainActivityViewModel.kt:24)
    at com.shahid.timerlivedata.MainActivity.onCreate(MainActivity.kt:32)
    at android.app.Activity.performCreate(Activity.java:6679)
    at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1118)
    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2618)
    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2726) 
    at android.app.ActivityThread.-wrap12(ActivityThread.java) 
    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1477) 
    at android.os.Handler.dispatchMessage(Handler.java:102) 
    at android.os.Looper.loop(Looper.java:154) 
    at android.app.ActivityThread.main(ActivityThread.java:6119) 
    at java.lang.reflect.Method.invoke(Native Method) 
    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:886) 
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:776) 
Debugger is no longer active
Starting a blocking GC Instrumentation

Here is my activity_main.kt

<?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:id="@+id/main"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">

    <TextView
        android:id="@+id/txtCount"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="0"
        android:textSize="34sp"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintVertical_bias="0.155" />

    <EditText
        android:id="@+id/edtCount"
        android:layout_width="wrap_content"
        android:layout_height="48dp"
        android:layout_marginTop="52dp"
        android:ems="10"
        android:hint="Enter timer in sec."
        android:inputType="text"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintHorizontal_bias="0.497"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/txtCount" />

    <Button
        android:id="@+id/btnStart"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="212dp"
        android:text="Start"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/edtCount" />

    <Button
        android:id="@+id/btnStop"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="44dp"
        android:text="Stop"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/btnStart" />

</androidx.constraintlayout.widget.ConstraintLayout>

Here is another the ViewModel.kt

package com.shahid.timerlivedata

import android.os.CountDownTimer
import androidx.lifecycle.LiveData
import androidx.lifecycle.MutableLiveData
import androidx.lifecycle.ViewModel

class MainActivityViewModel : ViewModel() {

    lateinit var timer : CountDownTimer

    private var remaining_seconds = MutableLiveData<Int>()
    private var _finished = MutableLiveData<Boolean>()

    val finished : LiveData<Boolean>
    get() = _finished

   val _seconds : LiveData <Int>
   get() = remaining_seconds

    var timerValue = MutableLiveData<Long>()

   fun startTimer(){
        timer = object : CountDownTimer(timerValue.value!!.toLong(),1000) {
            override fun onTick(millisUntilFinished: Long) {
               val remainingTime = millisUntilFinished/1000
                remaining_seconds.value = remainingTime.toInt()
            }

            override fun onFinish() {
                _finished.value = true

            }

        }
    }
    fun stopTimer (){
        timer.cancel()
    }

}