Add root layout id.

app/src/main/res/layout/fragment_authentication_server.xml

 <?xml version="1.0" encoding="utf-8"?>
 <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
+    android:id="@+id/relative_layout"
     android:layout_width="match_parent"
     android:layout_height="match_parent">
     tools:context=".authentication.server.ui.ServerFragment">