"App keeps stopping" pop ups and give the error java.lang.RuntimeExcpetion

Issue

Whenever I run the project on the emulator, it gives me the error App keeps stopping and I can't run the app. There was no error when debugging the code. So I checked on the Logcat then it gives me the error java.lang.RuntimeException. I have no idea where the error is or is it a problem of the code at all? Please someone help me...

1. Main Activity code

    class MainActivity1 : AppCompatActivity() {
    override fun onCreate(savedInstanceState: Bundle?) {
    super.onCreate(savedInstanceState)
    setContentView(R.layout.activity_main)
   
    val circularProgressBar: CircularProgressBar = findViewById(R.id.circularProgressBar)
   
    circularProgressBar.setProgressWithAnimation(65f,1000)
   
    findViewById<SeekBar>(R.id.seekBarProgress).onProgressChanged{
        circularProgressBar.progress = it
    }
    }
    private fun SeekBar.onProgressChanged(onProgressChanged: (Float)-> Unit){
    setOnSeekBarChangeListener(object : SeekBar.OnSeekBarChangeListener {
            override fun onProgressChanged(seekBar: SeekBar?, progress : Int, 
    fromUser: Boolean) {
            onProgressChanged(progress.toFloat())
            }
   
            override fun onStartTrackingTouch(seekBar: SeekBar?) {
   
            }
   
            override fun onStopTrackingTouch(seekBar: SeekBar?) {
   
            }
        })
    }
   

   }

2. Logcat Image of the Logcat

Solution

You're calling setProgressWithAnimation on a null object. I suggest you not use findViewById. Use ViewBinding or at least kotlinx.

Answered By - Maede Jalali