Crashing in kitkat

[caadiq]

It worked in lollipop but it crashed in kitkat
Logcat shows error here
View view = inflater.inflate(R.layout.fragment_server, container, false);

and fragment_server.xml is

<LinearLayout 
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">

    <RelativeLayout 
        android:layout_width="match_parent"
        android:layout_height="0dp"
        android:layout_weight="1">

        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_centerInParent="true"
            android:textColor="@color/colorAccent"
            android:textStyle="bold"
            android:textSize="25dp"
            android:text="서버소개"/>

    </RelativeLayout>

    <RelativeLayout 
        android:layout_width="match_parent"
        android:layout_height="0dp"
        android:layout_weight="1"/>

</LinearLayout>

<RelativeLayout 
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <android.support.design.widget.FloatingActionButton
        android:id="@+id/fab"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerInParent="true"
        android:src="@drawable/icon_arrow_right"
        app:backgroundTint="@color/colorPrimaryDark"
        app:elevation="4dp"
        app:fabSize="normal"/>

    <com.github.fabtransitionactivity.SheetLayout
        android:id="@+id/sheetlayout"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_centerInParent="true"
        android:elevation="2dp"
        app:ft_container_gravity="center"
        app:ft_color="@color/colorPrimaryDark"/>

</RelativeLayout>