How to fix an error in main.xml after switching to android x?

Question

android studio

I set the target api 29, then fixed the code using the refactor -> migrate then android x. In Java, everything seems to be fine, but main.xml is a complete error. How to fix it?

PS it's interesting, but the apk file is being assembled, everything is without errors, etc., but when I try to run the application, it crashes without any notifications, etc. I think it's only in main.xml.
Here is the code itself:

<androidx.core.widget.DrawerLayout
  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/_drawer"
  android:layout_width="match_parent"
  android:layout_height="match_parent"
  tools:openDrawer="start">
  <android.support.design.widget.CoordinatorLayout
    android:layout_width="match_parent"
    android:layout_height="match_parent">
    <android.support.design.widget.AppBarLayout
      android:layout_width="match_parent"
      android:layout_height="wrap_content"
      android:theme="@style/AppTheme.AppBarOverlay">
      <android.support.v7.widget.Toolbar
        android:id="@+id/_toolbar"
        android:layout_width="match_parent"
        android:layout_height="?attr/actionBarSize"
        android:background="?attr/colorPrimary"
        app:popupTheme="@style/AppTheme.PopupOverlay"/>
    </android.support.design.widget.AppBarLayout>
    <LinearLayout
      android:layout_width="match_parent"
      android:layout_height="match_parent"
      android:orientation="vertical"
      app:layout_behavior="@string/appbar_scrolling_view_behavior">

      <LinearLayout
        android:id="@+id/vscroll2"
        android:layout_width="match_parent"
        android:layout_height="match_parent">

        <WebView
          android:id="@+id/webview2"
          android:layout_width="match_parent"
          android:layout_height="match_parent" />
      </LinearLayout>
    </LinearLayout>
    <android.support.design.widget.FloatingActionButton
      android:id="@+id/_fab"
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:layout_margin="16dp"
      android:layout_gravity="right|bottom"
      app:srcCompat="@drawable/ic_home_black"/>
  </android.support.design.widget.CoordinatorLayout>

  <LinearLayout
    android:id="@+id/_nav_view"
    android:layout_width="320dp"
    android:layout_height="match_parent"
    android:layout_gravity="start"
    android:background="#BE3C3C3C">

    <include layout="@layout/_drawer_main" />
  </LinearLayout>
</androidx.core.widget.DrawerLayout>