Help with Cisco UC540 MOH.

Evening everyone.

I have a Cisco uc540 in production at the moment. Several handsets across the place. At the moment I’ve got lavender fields default music on hold. I wanted to upload a new file for the MOH.

I’ve tried doing so but I just hear weird noises and muffles across the phone. It isn’t working.

Any ideas on what I’m doing wrong? I’ve converted MOH file to U-LAW WAV and just isn’t working....