The following classes could not be found:
- android.support.constraint.ConstraintLayout (    Add constraint-layout library dependency to the project, Fix Build Path, Edit XML, Create Class)
- android.support.design.widget.AppBarLayout (Fix Build Path, Edit XML, Create Class)
- android.support.design.widget.NavigationView (Fix Build Path, Edit XML, Create Class)
- android.support.v7.widget.RecyclerView (Fix Build Path, Edit XML, Create Class)
- android.support.v7.widget.Toolbar (Fix Build Path, Edit XML, Create Class)
- androidx.constraintlayout.ConstraintLayout (Fix Build Path, Edit XML, Create Class)
- androidx.core.widget.DrawerLayout (Fix Build Path, Edit XML, Create Class)
 Tip: Try to build the project.   Tip: Try to refresh the layout.