java.lang.ClassNotFoundException: Didn't find class "androidx.core.view.ViewPager" on path

I figure out problem, When we merger to androidx then android studio convert viewpager, swipe to refresh layout and some other views to androidx.core for example viewpager its looks like androidx.core.view.ViewPager but correct is androidx.viewpager.widget.ViewPager please check in your xml layouts and see there is right component is added or not if there is androidx.core then check for right one and replace it. And also import dependency

implementation 'com.google.android.material:material:1.1.0-alpha08

You need to below dependencies in your build.gradle file

implementation 'com.google.android.material:material:1.1.0