I'm getting this error message on every page where the player should be running:

Uncaught ReferenceError: album_player is not defined

I'm using:

Joomla!, 3.4.4.
and the latest version of JW player and music collection that you can download on your website.
The cache is desactivated on my webpage


Link to the webpage: http://xn--glisedejsuschristde-9ybi.apps-1and1.com/index.php/musiques/c/2-chants-d-assemblee-speciaux/1-eglise-de-jesus-christ-de-la-pentecote

I used debug on Chrome to debug and this is what i'm getting:

Uncaught ReferenceError: album_player is not defined
play_song_position @ playlist_functions.js:185
(anonymous function) @ VM1718:1

which come from this:
function play_song_position(position){
//new in 2.4

if(currentItem == position) album_player.play();
else album_player.playlistItem(position);
}

I'm not a developer so i can't go much deeper..