The player won't play SOME of the WMA files. I get this error message:
Unable to open item for playback (IWMSyncReader::OpenStream failed : Unknown error code (0xC00D0BBD)):

Other players (such as WMP) can play it. Does anyone know why this might be? On a side note this music is something I ripped, using WMP, from a CD I bought. Not so sure if that's relevant but... yeah...

Thanks!

That means your WMA files are DRM protected, which is not supported by foobar2000.

You need to re-rip them with copy protection disabled.

Oh, thank you very much ^^