Export/Mixdown AIF and Wav files are completely silent?

Hi, I currently working on a film project in adobe audition and every time I export/mixdown the entire session (either in wav or aif) I get a completely silent file. I have all of my audio tracks routed to 5.1 buses for dialog, SFX, Music, foley and ambiences. The 5.1 buses are routed to a L&R Print Master (stereo bus) which is routed to the Master Track (which is 5.1). I've tried exporting/mixing down the Master track to 5.1 and stereo as well as the L&R PrintMaster (stereo bus) and they all come out silent.

I've also tried creating a new session with all the audio tracks being routed to their respective 5.1 buses for dialog, SFX, foley, music and ambiences. The 5.1 buses are routed to a 5.1 PrintMaster bus (5.1 bus) which is routed to the stereo Master track. Even in this situation I get silent WAV and AIF files when I export/mixdown the Master track as well as the 5.1 print master.

does anybody know what I'm doing wrong? Note: none of the buses or audio tracks are soloed.