I'm the commissioner right? Think so anyway.
Nope on the playoff picks, I didn't select that as an option for our group (don't remember it even being there at the start of the season) and haven't 'turned it on' so no idea why you're getting the message you are. As far as I know, you won, so congratulations btw.
I guess keep an eye on it to see if it changes anything and you can make picks later this week but as of right now I can't make picks either and I don't think anyone can unless I enable that option which I honestly don't consider to be part of the Pick 'Em pool.