A long shot but one possible cause that has not been mentioned would be the actual
FX “units” IO patching. When you open up your FX processor on the right hand side there is a front panel/back panel tab.
Hitting that will flip the unit around and let you re-patch the input and output routing
from the normally assigned FX mixes and returns.
Again it’s a long shot but if someone was messing around with the mixer who knows what they could have gotten into.
If you got the top layer with the mix sends and returns do you see any level
indication on the FX return channels?
PAFL the FX send masters and using headphones do you hear any audio?
PAFL the FX return channels and using headphones do you hear any audio?
If you hear audio on a PAFL FX return but not in the main mix go back and double
check that the returns are assigned to the main LR mix.
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