I have a BaseFragment which extends from Fragment

open class BaseFragment: Fragment {
        constructor() : super()
        .....
}

And then FragmentA which extends from BaseFragment

open class FragmentA: BaseFragment {
        constructor() : super()
        .......
        companion object {
        fun getInstance() : FragmentA {
            return FragmentA()
        }
    }
}

And in my ActivityA I have a function which is

private fun replaceCurrentFragment(fragment: Fragment) {
        Log.v(LOG_TAG, “replaceCurrentFragment”)
        val fragmentManager = supportFragmentManager;
        val transaction = fragmentManager.beginTransaction()
        transaction.replace(R.id.master_fragment_view, fragment)
        transaction.commit()
    }

but when i call i get an error like attached image, searched alot but could not find anything. Thanks in advance. BTW I realized that if I change FragmentA : Fragment then it works!