diff --git a/WebCast/src/main/java/com/github/warren_bank/webcast/exoplayer2/FullScreenManager.java b/WebCast/src/main/java/com/github/warren_bank/webcast/exoplayer2/FullScreenManager.java
index 3676d95..99654c5 100644
--- a/WebCast/src/main/java/com/github/warren_bank/webcast/exoplayer2/FullScreenManager.java
+++ b/WebCast/src/main/java/com/github/warren_bank/webcast/exoplayer2/FullScreenManager.java
@@ -6,7 +6,6 @@
 import android.app.Dialog;
 import android.view.View;
 import android.view.ViewGroup;
-import android.widget.FrameLayout;
 import android.widget.ImageView;
 import com.google.android.exoplayer2.ui.PlaybackControlView;
 import com.google.android.exoplayer2.ui.PlayerView;
@@ -19,7 +18,7 @@ final class FullScreenManager {
   private PlayerView localPlayerView;
   private Dialog mFullScreenDialog;
   private ImageView mFullScreenIcon;
-  private FrameLayout mFullScreenButton;
+  private ViewGroup mFullScreenButton;
 
   // static factory
 
@@ -82,7 +81,7 @@ public void onBackPressed() {
   }
 
   private void openFullscreenDialog() {
-    ((ViewGroup) localPlayerView.getParent()).removeView(localPlayerView);
+    ((ViewGroup) localPlayerView.getParent()).removeView(localPlayerView);                     // FrameLayout
     mFullScreenDialog.addContentView(localPlayerView, new ViewGroup.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.MATCH_PARENT));
     mFullScreenIcon.setImageDrawable(ContextCompat.getDrawable(videoActivity, R.drawable.ic_fullscreen_close));
     isFullScreen = true;
@@ -90,17 +89,18 @@ private void openFullscreenDialog() {
   }
 
   private void closeFullscreenDialog() {
-    ((ViewGroup) localPlayerView.getParent()).removeView(localPlayerView);
-    ((FrameLayout) videoActivity.findViewById(R.id.main_media_frame)).addView(localPlayerView);
+    ((ViewGroup) localPlayerView.getParent()).removeView(localPlayerView);                     // Dialog
+    ((ViewGroup) videoActivity.findViewById(R.id.main_media_frame)).addView(localPlayerView);  // FrameLayout
     isFullScreen = false;
     mFullScreenDialog.dismiss();
     mFullScreenIcon.setImageDrawable(ContextCompat.getDrawable(videoActivity, R.drawable.ic_fullscreen_open));
   }
 
   private void initFullscreenButton() {
-    PlaybackControlView controlView = localPlayerView.findViewById(R.id.exo_controller);
-    mFullScreenIcon = controlView.findViewById(R.id.exo_fullscreen_icon);
-    mFullScreenButton = controlView.findViewById(R.id.exo_fullscreen_button);
+    PlaybackControlView controlView;
+    controlView       = (PlaybackControlView) localPlayerView.findViewById(R.id.exo_controller);
+    mFullScreenIcon   = (ImageView) controlView.findViewById(R.id.exo_fullscreen_icon);
+    mFullScreenButton = (ViewGroup) controlView.findViewById(R.id.exo_fullscreen_button);      // FrameLayout
     mFullScreenButton.setOnClickListener(new View.OnClickListener() {
         @Override
         public void onClick(View v) {
diff --git a/WebCast/src/main/java/com/github/warren_bank/webcast/exoplayer2/PlayerManager.java b/WebCast/src/main/java/com/github/warren_bank/webcast/exoplayer2/PlayerManager.java
index cb74b1c..00075ca 100644
--- a/WebCast/src/main/java/com/github/warren_bank/webcast/exoplayer2/PlayerManager.java
+++ b/WebCast/src/main/java/com/github/warren_bank/webcast/exoplayer2/PlayerManager.java
@@ -7,6 +7,7 @@
 import androidx.annotation.Nullable;
 import android.view.KeyEvent;
 import android.view.View;
+import android.view.ViewGroup;
 
 import com.google.android.exoplayer2.C;
 import com.google.android.exoplayer2.DefaultRenderersFactory;
@@ -452,11 +453,11 @@ private void setCurrentPlayer(Player currentPlayer) {
     // View management.
     if (currentPlayer == exoPlayer) {
       fullScreenManager.enable();
-      localPlayerView.setVisibility(View.VISIBLE);
+      ((ViewGroup) localPlayerView.getParent()).setVisibility(View.VISIBLE);  // FrameLayout
       castControlView.hide();
     } else /* currentPlayer == castPlayer */ {
       fullScreenManager.disable();
-      localPlayerView.setVisibility(View.GONE);
+      ((ViewGroup) localPlayerView.getParent()).setVisibility(View.GONE);     // FrameLayout
       castControlView.show();
     }
 
diff --git a/WebCast/src/main/java/com/github/warren_bank/webcast/exoplayer2/VideoActivity.java b/WebCast/src/main/java/com/github/warren_bank/webcast/exoplayer2/VideoActivity.java
index 0d3425c..4ad5723 100644
--- a/WebCast/src/main/java/com/github/warren_bank/webcast/exoplayer2/VideoActivity.java
+++ b/WebCast/src/main/java/com/github/warren_bank/webcast/exoplayer2/VideoActivity.java
@@ -65,7 +65,7 @@ public void onCreate(Bundle savedInstanceState) {
 
     setContentView(R.layout.video_activity);
 
-    Toolbar toolbar = findViewById(R.id.toolbar);
+    Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
     setSupportActionBar(toolbar);
     getSupportActionBar().setTitle("");
     toolbar.setNavigationIcon(R.drawable.ic_arrow_back);
@@ -76,12 +76,12 @@ public void onClick(View v) {
       }
     });
 
-    localPlayerView = findViewById(R.id.local_player_view);
+    localPlayerView = (PlayerView) findViewById(R.id.local_player_view);
     localPlayerView.requestFocus();
 
-    castControlView = findViewById(R.id.cast_control_view);
+    castControlView = (PlayerControlView) findViewById(R.id.cast_control_view);
 
-    mediaQueueList = findViewById(R.id.sample_list);
+    mediaQueueList = (RecyclerView) findViewById(R.id.sample_list);
     ItemTouchHelper helper = new ItemTouchHelper(new RecyclerViewCallback());
     helper.attachToRecyclerView(mediaQueueList);
     mediaQueueList.setLayoutManager(new LinearLayoutManager(this));
diff --git a/constants.gradle b/constants.gradle
index 39e0699..79b7880 100644
--- a/constants.gradle
+++ b/constants.gradle
@@ -1,6 +1,6 @@
 project.ext {
-    releaseVersionCode = 004070016
-    releaseVersion = '004.07.00-16API'
+    releaseVersionCode = 004070116
+    releaseVersion = '004.07.01-16API'
     minSdkVersion = 16
     targetSdkVersion = 28
     compileSdkVersion = 28