diff -r 6ddc52965fb8 -r e234339fe8df cms/app-client/app/services/player.js
--- a/cms/app-client/app/services/player.js	Thu Aug 25 19:10:41 2016 +0200
+++ b/cms/app-client/app/services/player.js	Fri Aug 26 11:42:10 2016 +0200
@@ -7,7 +7,7 @@
     model: null,
     transcript: null,
 
-    window: '',
+    window: false,
     playing: false,
     progress: 0, // In Milliseconds
     videoscreen: false,
@@ -28,7 +28,7 @@
          if(this.get('window') !== el) {
             this.set('window', el);
         } else {
-            this.set('window', '');
+            this.set('window', false);
         }
     },