That's pretty much it. LMMS doesn't make any sounds. Which makes the program very difficult to use.
I don't understand why. Literally every other program on my computer plays sounds fine. Including Firefox, Chrome, Spotify, Audacity (with ALSA).
I have a very normal setup. Haven't mucked around with any settings. LMMS was installed with apt-get install lmms.
Ubuntu 16.10, LMMS 1.1.3. Let me know if you want other info.

