No sound coming out of already mixed garageband file

Okay so here's my dilemma. I recorded an entire song in garage band, mixed it down and now have the itunes file. I went back to listen to it again in garageband to make some edits and stuff and now no sound comes out at all.

My preferences are fine, it is set to built in output. What really freaks me out is if I open any of my past projects, all the sound works for them. But the second I open this one no sound comes out, even though every channel shows the volume going up just like the song is playing. Nothing is set on solo or mute, I checked every single channel. And there is no ducking going on.

My question is did I hit something without even knowing it? It's just a really odd problem I cannot firugre out and it is driving me insane.

Any help greatly appreciated!