how to play wav files in apple mail

We have just upgraded our iMacs from 10.6.8 to 10.10.1 and since that upgrade we are not able to play Wav files in Apple mail (Apple Mail 8.1).

They are attached in mail, and before (with 10.6.8 and mail 4.6 (1085)) it worked just fine.

We have encountered this problem with: iMacs (late 2013) and Macbooks with 10.9.5 (and newer). The play button is visible in the email message but when clicked no programs are started. You can see a physical reaction though when the button is clicked so its not just a static picture.

When i rightclick the attachment, and save to Desktop, i am able to play the file with iTunes or VLC.

I hope someone can tell me what the solution is (or guide me in the right direction) so i can play from my mail instantly.

playbutton in mail 4.6 (which works fine)

playbutton in mail 8.1 (which doesn't work)

Note that this black button also says: Laden, which means Loading but nothing happens.

Greetings,

Martin