McDonald's tweeted an apology on Sunday night after the fast food chain drastically underestimated demand for the Szechuan McNugget sauce.
McDonald's had offered the sauce on Saturday at select locations. But unlike other limited offerings, the lure of Szechuan McNugget sauce led to not only massive lines but also guests in costumes.
The promotion came after a massive demand from fans of the Adult Swim cartoon "Rick and Morty," according to Business Insider.
The problem was that McDonald's only had a small amount of the sauce at the select locations compared to the demand and left patrons frustrated.
In some places, police needed to get involved to help control angry customers.
— Ian ??? Sikes (@ianjsikes) October 7, 2017
McDonald's admitted its mistake and vowed to do better by bringing sauce back to all restaurants this winter.
— McDonald's (@McDonalds) October 8, 2017