Ok! The L4D server issues have been solved!!! Turns out it was a loose nut behind the keyboard.
Valve’s keyboard.
Seems there was a requirement change for LDS systems and for some reason Valve decided not to tell us about it. Very nice of Valve to do that. We got the L4D1 server to run again. Will install the 2nd one later today.
I didn’t think it was possible to be happy and pissed at the same time.