It definitely supports mp3 and m4a. Any more details on the file? Do you know what bit rate it is?
Thanks for your answer.
That's strange beacause on LIghtroom 4, I was using it regularly...
Sorry I don't know. How can I know the bit rate ?
I've tried with several musics with no success.
If you look at the music file in itunes or other player it should say there. Try restarting the computer.
I don't have itunes.
I followed your advise and restarted but nothing changed...
I will work with Movie Maker instead.
Thank you very much for your help.