well the OP's problem might be resolved but i have the same issue with a different cause so i might hijack the name
i know the symptom but not the cause. i need the steam game server uid line to pop up in the console but it stops short "game engine initialization completed"
any reason that would prevent the server connecting to steam and making itself known? i watched
https://www.youtube.com/watch?v=RosSDkmlVqo this video and his gets a UID on first run? i HAD a server running wednesday night and played a few games before leaving it online for others to join overnight. it stopped working at 530 am the next day but i assumed that was the fibre exchange upgrade schedulled for 5-8am.
edit:apparantly running appupdate with validate for the sixth or seventh time finally found some dodgy files to reacquire and i'm back online.