Record with music playback in Mixcraft?

I'm using Mixcraft for recording. It was good, but lately there've been some problems. While I'm playing the playback music (instrumental as .mp3 or .wma) and I want to start record, the music stops and I can't hear anything. If I stop recording, it returns as normal. Can someone help me with that? I'm in need of recording something for a cl project. Thank you.