Open the layout in Java. Lang. NullPointerException-CodePudding

On the open making download open source project, most of the layout opens an error:
 
Render problem: 
java.lang.NullPointerException   at android.view.ViewGroup.brokenDispatchApplyWindowInsets(ViewGroup.java:7200)   at android.view.ViewGroup.dispatchApplyWindowInsets(ViewGroup.java:7193)   at android.view.ViewGroup.brokenDispatchApplyWindowInsets(ViewGroup.java:7203)   at android.view.ViewGroup.dispatchApplyWindowInsets(ViewGroup.java:7193)   at android.view.ViewGroup.brokenDispatchApplyWindowInsets(ViewGroup.java:7203)   at android.view.ViewGroup.dispatchApplyWindowInsets(ViewGroup.java:7193)   at android.view.ViewGroup.brokenDispatchApplyWindowInsets(ViewGroup.java:7203)   at android.view.ViewGroup.dispatchApplyWindowInsets(ViewGroup.java:7193)   at android.view.ViewRootImpl.dispatchApplyInsets(ViewRootImpl.java:1925)   at android.view.ViewRootImpl_Accessor.dispatchApplyInsets(ViewRootImpl_Accessor.java:24)   at com.android.layoutlib.bridge.impl.Layout.requestFitSystemWindows(Layout.java:385)   at android.view.View.requestFitSystemWindows(View.java:10796)   at android.view.View.requestFitSystemWindows(View.java:10796)   at android.view.View.requestFitSystemWindows(View.java:10796)   at android.view.View.requestApplyInsets(View.java:10804)   at androidx.core.view.ViewCompat.requestApplyInsets(ViewCompat.java:2426)   at androidx.core.view.ViewCompat$Api21Impl$1.onApplyWindowInsets(ViewCompat.java:4774)   at android.view.View.dispatchApplyWindowInsets(View.java:10514)   at android.view.ViewGroup.dispatchApplyWindowInsets(ViewGroup.java:7191)   at android.view.ViewGroup.brokenDispatchApplyWindowInsets(ViewGroup.java:7203)   at android.view.ViewGroup.dispatchApplyWindowInsets(ViewGroup.java:7193)   at android.view.ViewGroup.brokenDispatchApplyWindowInsets(ViewGroup.java:7203)   at android.view.ViewGroup.dispatchApplyWindowInsets(ViewGroup.java:7193)   at android.view.ViewGroup.brokenDispatchApplyWindowInsets(ViewGroup.java:7203)   at android.view.ViewGroup.dispatchApplyWindowInsets(ViewGroup.java:7193)   at android.view.ViewRootImpl.dispatchApplyInsets(ViewRootImpl.java:1925)   at android.view.ViewRootImpl_Accessor.dispatchApplyInsets(ViewRootImpl_Accessor.java:24)   at com.android.layoutlib.bridge.impl.Layout.requestFitSystemWindows(Layout.java:385)   at android.view.View.requestFitSystemWindows(View.java:10796)   at android.view.View.requestFitSystemWindows(View.java:10796)   at android.view.View.requestFitSystemWindows(View.java:10796)   at android.view.View.requestApplyInsets(View.java:10804)   at androidx.core.view.ViewCompat.requestApplyInsets(ViewCompat.java:2426)   at androidx.coordinatorlayout.widget.CoordinatorLayout.onAttachedToWindow(CoordinatorLayout.java:276)   at android.view.View.dispatchAttachedToWindow(View.java:19575)   at android.view.ViewGroup.dispatchAttachedToWindow(ViewGroup.java:3430)   at android.view.ViewGroup.dispatchAttachedToWindow(ViewGroup.java:3437)   at android.view.ViewGroup.dispatchAttachedToWindow(ViewGroup.java:3437)   at android.view.ViewGroup.dispatchAttachedToWindow(ViewGroup.java:3437)   at android.view.AttachInfo_Accessor.setAttachInfo(AttachInfo_Accessor.java:44)
For what is this