Sounds like you have the Silence playback template applied. With that template, no MIDI would be generated. Try Play → Playback Template, choose Auto then Apply and Close..
Sorry to say, it plays back just fine for me. If you go to Play mode and click the ‘e’ next to Halion, what instruments are loaded in the slots? In my instance, strangely there are 12 slots filled for 4 instruments.
EDIT: I re-applied the Auto template and, again, strange, it didn’t load Groove Agent for the drums even though I have that checked in the Auto template, rather, it loaded a bunch of GM kits into Halion (hence the number of occupied slots).
Upload your diagnostics (Do Help>Create Diagnostic Report and upload the zip file from your desktop), so one of the team can take a look at your set up.
i already downloaded some stuff and i have a couple of sounds, now, so it’s improving! now my document doesn t seem to link the instruments to the sounds.
i can do it manually (although i m not sure how) but i suppose it should be automatic, right?
when i click the e of halion sonic, the app is empty, i mean there are no instruments on the window. on the right there s a list of possibilities, and i can insert channel after channel all the instruments. but i dont think it s the proper method.