I made this post rather than answer to the thread of MisterC cause it's a bit different.
It was about a week or 2 that I didn't use my KPA. I turn in on this morning and no of any outputs worked (headphones too). I rebooted KPA 2 times with, the 2nd time all cables unplugged excepted input and, that worked excepted the Direct Output.
I exchanged some emails with Davide at a time about a problem with the Direct Output and he advised me to insert a loop Mono in a the slot A.
I tried it and I got the Direct output back. I have a to put the mix of the loop at 0% if I didn't want to have a SHHHH.
I just turn off the loop by pressing the A button, got a big clip ( ) in my monitoring and... direct output was back, clearer than with the loop mono ON. I browsed throught presets, so, the loop mono isn't there anymore and direct output works now as i should be.
Really strange .