no sound [fixed, but after an hour wasted]

last night i was working on an almost-finished project, when all the sudden (so it seemed) none of my tracks would make any sound . . . so i'm like "what the ...?" i at first thought that it could be something with Maschine 1.6 (because it just came out of beta, and i had had an unexplainable problem with the beta a couple months ago doing something to my audio drivers in Sonar).  what turned out to be the problem was this: i had inserted a new audio track, for the purpose of being able to move some clips around, and the audio track, by default, was set up to be sent to the METRONOME BUS! why would anything ever be set up to go by default to the Metronome Bus? so once i detected that, and sent it to MASTER, all my audio/midi once again made sound!

just thought i'd post this as something possibly to look for if audio stops making sound

why would anything ever be set up to go by default to the Metronome Bus?

Most likely because it was inadvertently made the default bus in that project. Right-click your Metronome bus, and if there is a check next to "Set as Default Bus", that's the problem. Just right-click the Master, and set it as the default.

I had the same problem a while back.  All new audio tracks were being set to my "Vocal" buss.  It was because I had inadvertently set the default to that when creating my "Normal" template.