Null Pointer Exception, Why?

[ElioReyesGlez]

kotlin.KotlinNullPointerException
at com.yalantis.filter.widget.Filter.onSaveInstanceState(Filter.kt:349)
at android.view.View.dispatchSaveInstanceState(View.java:20650)
at android.view.ViewGroup.dispatchSaveInstanceState(ViewGroup.java:3961)
at android.view.ViewGroup.dispatchSaveInstanceState(ViewGroup.java:3967)
at android.view.View.saveHierarchyState(View.java:20633)
at androidx.fragment.app.FragmentStateManager.saveViewState(FragmentStateManager.java:721)
at androidx.fragment.app.FragmentStateManager.moveToExpectedState(FragmentStateManager.java:330)
at androidx.fragment.app.FragmentManager.executeOpsTogether(FragmentManager.java:2189)
at androidx.fragment.app.FragmentManager.removeRedundantOperationsAndExecute(FragmentManager.java:2106)
at androidx.fragment.app.FragmentManager.execPendingActions(FragmentManager.java:2002)
at androidx.fragment.app.FragmentManager$5.run(FragmentManager.java:524)
at android.os.Handler.handleCallback(Handler.java:938)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:223)
at android.app.ActivityThread.main(ActivityThread.java:7656)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:592)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:947)