Exporting SESX to make a MP3 file

[ReyMonroy7]

I'm having trouble converting my SESX file to an MP3. I've followed all the steps of a bunch of different videos I've seen and can't seem to get it right. I got to Export then Multitrack Mixdown to select the entire session and it doesnt allow to choose that option. I've seen that it needs to be "master" but when I go to my audio hardware it doesnt show anything that says something like that. Once I was done recording I saved the file and disconnected my aggregate device of my microphones and closed adobe audition. I eventually reopneed the file and haven't gotten it to export as an MP3. I am new to this program and any information or steps that can help me would be very appreciated. 

[SteveG_AudioMasters_]

Let's get the terminology right - you aren't 'converting' an .sesx file to anything - it has no audio in it at all, just instructions for what tracks to play out when, onto your final mp3, or whatever, file. It's important to understand how this works, because it can give you clues as to what might be happening. I can't really see enough of your track controls to tell where the output is being assigned to, but one thing I can see is that both tracks are still record-enabled - I haven't ever tried this, but this might well be enough to stop them exporting; you need to click those both off. If you expand the tracks slightly, you'll see where the output is being sent to, and if you have altered nothing, it should say 'Master':

I've ringed the R button you should click on, and expanding the track slightly will reveal its output destination. 'Master' in this sense has nothing to do with hardware; you don't need any hardware connected at all to export to an output file, just the correct track routing.