BV512 Cutting Out Mix

[PaulD]

I have a mix of a song that includes one vocal track and several instruments that works fine. I decided to try the BV512 vocoder on the vocal track. Everything worked well and I got the effect that I wanted using the vocoder on the vocal track. But when I tried to play the whole mix, the vocoder audio track would only play if it's soloed and that cut out the entire rest of the mix. When I play the mix without the vocoder tracks soloed, there is no sound at all from the vocoded audio track. Any ideas what could cause this?

Thanks