Unsupported Audio Format - Use Pulse Audio Code Manipulation (PCM) If Available

I just reinstalled ubuntu on my dell xps 13 which I have connected to my dell u3417w monitor. The sound used to work fine on the monitor before I reinstalled the OS but now I'm getting a message every time I start up the monitor. It says:

Unsupported Audio Format - Use Pulse Audio Code Manipulation (PCM) If Available

Any help?