No sound comming through bus
 

Hi everybody,

I have a problem with a specific session in Protools, with receiving audio on several internal busses.
It should be impossible i suppose, because it's an internal routing, I just send audio from one or more tracks to an internal bus (like a VCA/DCA), and then send this bus to let's say the mix bus/ physical output.
After working fine for a while, suddenly when starting the session the next day, several busses do not receive the internal signals.
Some busses will work/receive again after making them inactive and then active again, but not the mix bus so no sound comes through.
In other session there is no such problem.
So i went and created a new blank session and imported all the tracks from the session i was working on. Then it worked, but only for a while and then the same problem happens again.
The internal routing seems to be fine to me.
If i make a new audio track end send it straight to the physical output, still no signal.
If i make a new audio track end send it to another track through a bus, no signal comes there.
Any suggestions? It's driving me nuts.