Action bar has unknown black text.

This is my simple implementation of blur dialog with my custom layout, and you can see the image. How to get rid of the text here. ?

public class PatternBlurDialog extends SupportBlurDialogFragment {
    List<PatternLockView.Dot> recorderPattern;
    PreferenceHelper preferenceHelper = App.getPreferences();

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
    }

    @Nullable
    @Override
    public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
        return inflater.inflate(R.layout.dialog_pattern_lock, container, false);
    }

    @Override
    public void onViewCreated(View view, @Nullable Bundle savedInstanceState) {
        super.onViewCreated(view, savedInstanceState);

        PatternLockView lockView = (PatternLockView) view.findViewById(R.id.pattern_lock_view);
        TextView header = (TextView) view.findViewById(R.id.pattern_header);

    }

    @Override
    protected float getDownScaleFactor() {
        // Allow to customize the down scale factor.
        return 5.0f;
    }

    @Override
    protected int getBlurRadius() {
        // Allow to customize the blur radius factor.
        return 7;
    }

    @Override
    protected boolean isActionBarBlurred() {
        // Enable or disable the blur effect on the action bar.
        // Disabled by default.
        return true;
    }

    @Override
    protected boolean isDimmingEnable() {
        // Enable or disable the dimming effect.
        // Disabled by default.
        return true;
    }

    @Override
    protected boolean isRenderScriptEnable() {
        // Enable or disable the use of RenderScript for blurring effect
        // Disabled by default.
        return true;
    }

    @Override
    protected boolean isDebugEnable() {
        // Enable or disable debug mode.
        // False by default.
        return true;
    }
}[

screenshot_20170810-152050 ](url)

tvbarthel / BlurDialogFragment

Action bar has unknown black text. #87