Everything in treble clef sounds fine, but I can't get any sound when I play the bass track. I changed the strings and they aren't even super low notes, so what gives?
Actually, neither of those was the issue. But I clicked "Show Matrix," unclicked these two blue bars, and clicked them again, and it worked. I'm still not sure how that happened though....
Was this a tab you downloaded or made yourself? Possibly what happened was that the volume for the bass track was set to 'ppp.' I've run into that on occasion with various tracks and changed it back to 'f' and that solved the problem.