I am passing arguments using safeargs. In the reciving fragment I am getting a compile error: 'Required Bundle Found Bundle?'. Cannot see where the error has crept in.

Googled around, checked text and udacity tutorial

Where error appears (at 'arguments')

package com.example.android.naveditoryoutube

import android.arch.lifecycle.ViewModelProviders
import android.os.Bundle
import android.support.v4.app.Fragment
import android.view.LayoutInflater
import android.view.View
import android.view.ViewGroup
import kotlinx.android.synthetic.main.fragment_two_fragment.*

class FragmentTwo : Fragment() {

    companion object {
        fun newInstance() = FragmentTwo()
    }

    private lateinit var viewModel: FragmentTwoViewModel

    override fun onCreateView(
        inflater: LayoutInflater, container: ViewGroup?,
        savedInstanceState: Bundle?
    ): View? {
        return inflater.inflate(R.layout.fragment_two_fragment, container, false)
    }

    override fun onActivityCreated(savedInstanceState: Bundle?) {
        super.onActivityCreated(savedInstanceState)
        viewModel = ViewModelProviders.of(this).get(FragmentTwoViewModel::class.java)

    }

    override fun onStart() {
        super.onStart()
        var args = FragmentTwoArgs.fromBundle(arguments)
        argText.text = args.calculated_Number
    }

}

Sending code:

package com.example.android.naveditoryoutube

import android.arch.lifecycle.ViewModelProviders
import android.os.Bundle
import android.support.v4.app.Fragment
import android.view.LayoutInflater
import android.view.View
import android.view.ViewGroup
import android.widget.Button
import androidx.navigation.Navigation
import kotlinx.android.synthetic.main.fragment_one_fragment.*


class FragmentOne : Fragment() {


    companion object {
        fun newInstance() = FragmentOne()
    }

    private lateinit var viewModel: FragmentOneViewModel


    override fun onCreateView(
        inflater: LayoutInflater, container: ViewGroup?,
        savedInstanceState: Bundle?
    ): View? {



        return inflater.inflate(R.layout.fragment_one_fragment, container, false)

    }

    override fun onActivityCreated(savedInstanceState: Bundle?) {
        super.onActivityCreated(savedInstanceState)
        viewModel = ViewModelProviders.of(this).get(FragmentOneViewModel::class.java)

        var calculated_Number : String = viewModel.sendNewNumber().toString()

        button_calculate.setOnClickListener{view: View ->
            if (number_box.text.isNotEmpty()){
                var number_entered: String = number_box.text.toString()
                viewModel.findNewNumber((number_entered))
                calculated_Number = viewModel.sendNewNumber()
               Navigation.findNavController(view).navigate(FragmentOneDirections.actionFragmentOneToFragmentTwo(calculated_Number))
            }


        }
    }

}

Error appears here var args = FragmentTwoArgs.fromBundle(arguments)

arguments is expected to be Bundle but is Bundle?