Sleeping at Muzdalifah border
It has been quoted in a fatwa book of hajj and umrah that was released by The Ministry of Endowment and Islamic Affairs at Kuwait:
The majority of jurists (the Hanafi, Maliki and Shafi’i unanimously said, which is also a narration from Ahmad) that they are of the view that staying overnight in Muzdalifah for the pilgrim on the night of sacrifice is Sunnah, so there is no obligation for sacrificing anything as penalty, either with or without an excuse.
And some Shafi’i jurists are of the more correct view, which is also the doctrine of the Hanbalis, that it is obligatory to leave blood (i.e. sacrifice animal as penalty), if there is no excuse, but if there is an excuse, nothing is required. Cases of error or the lack of space in the time of crowd are acceptable excuses for not staying overnight.