ListPreference not showing by clicking on preference screen

Nothing Happens on clicking ListPreference on Preference screen No entries are shown to select

android 4.4

<PreferenceCategory
        android:title="Image"
        android:key="image">
    <ListPreference
                android:title="Flash"
                android:key="flash"
                android:defaultValue="Off"
                android:entries="@array/flash"
                android:entryValues="@array/flash_values"
                android:persistent="true"/>
    </PreferenceCategory>

Array values file

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <string-array name="opts">
        <item>auto</item>
        <item>50</item>
        <item>100</item>
        <item>200</item>
        <item>400</item>
        <item>800</item>
    </string-array>

    <string-array name="opts_values">
        <item>auto</item>
        <item>50</item>
        <item>100</item>
        <item>200</item>
        <item>400</item>
        <item>800</item>
    </string-array>

    <string-array name="flash">
        <item>Auto</item>
        <item>On</item>
        <item>Off</item>
    </string-array>

    <string-array name="flash_values">
        <item>0</item>
        <item>1</item>
        <item>2</item>
    </string-array>
</resources>

Title is correctly shown but nothing happens on clicking the preference. No error while building. Preference List is not shown as dialog. All other types are working correctly.