Uber Diablo didn't spawn??

Watching D2R Clone hunters, i set up my game last night. 6 hours later i woke up, even had the Diablo invades sanctuary message. Go to Arcane Sanctuary and back through portal - no super unique. Confused, clear level, nothing. Go to Stony Field - no super unique. Rakanishu is not there. Go to a5, Eldritch the Rectifier IS there. Where the heck is Uber Diablo? I've never done this before but the guides all say this should work.