UEFA were forced to redraw the Champions League round of 16 draw in its entirety after Manchester United were incorrectly left out of part of it before being handed a nightmare tie against Paris Saint-Germain.

"Following a technical problem with the software of an external service provider that instructs the officials as to which teams are eligible to play each other, a material error occurred in the draw for the UEFA Champions League Round of 16," UEFA said in a statement. "As a result of this, the draw has been declared void and will be entirely redone at 15:00 CET (9 a.m. ET)."

You can watch the draw (again) on CBS Sports HQ and Paramount+.

What went wrong?

United were first incorrectly placed in the draw against Villarreal, who they could not face having played them in Group F. Andrey Arshavin would take their name from the pot meaning that that particular tie had to be redrawn with City handed the fixtures with the Europa League holders. 

Craving even more coverage of the world's game? Listen below and follow ¡Qué Golazo! A Daily CBS Soccer Podcast where we take you beyond the pitch and around the globe for commentary, previews, recaps and more.

The confusion did not end there, however. Images showed that United's ball was subsequently left out of those that could have been drawn to play Atletico Madrid, whose group stage opponents Liverpool were put into the pot from which former Arsenal forward Arshavin drew. From that stage onwards the entire draw was compromised.

It had been suggested that UEFA would simply restart the draw from that point however they instead opted to simply do it all again.

What will it mean for clubs in the draw?

The draw will be welcome news for United and Atletico Madrid, who were handed a match against Bayern Munich. Another meeting of Lionel Messi and Cristiano Ronaldo was certainly the stand out of the eight knockout ties with further added drama in a matchup between former Real Madrid defenders Sergio Ramos and Raphael Varane. Add to that PSG head coach Mauricio Pochettino pitting his wits against a club who have long coveted him and there were talking points aplenty.

Atletico were among the few clubs to publicly express their displeasure with the draw, little wonder as they had been handed a tie with one of the favorites to win the Champions League. Prior to UEFA's announcement they had demanded "explanations and a solution" from European football's governing body.

Meanwhile the Premier League's three leading lights may be cursing their misfortune after what appeared to be favorable draws were taken off the table. In particular Chelsea, who could only have been paired with Real Madrid, Bayern Munich, Ajax and Lille, will be fearing what comes next after missing out on a tie with the latter of that quartet. Liverpool and Manchester City should still be expecting favorable draws after topping their groups.

Not only that but they have lost out on three ties -- Manchester United vs. Paris Saint-Germain, Ajax vs. Inter Milan and Bayern Munich vs. Atletico Madrid -- that pitted potential favorites or dark horses against each other. However City head coach Pep Guardiola was magnanimous, saying: "[The draw is] going to happen again, I think it's fair. It was a mistake, these kind of things sometimes happen, especially with players and managers and sometimes UEFA too."

Real Madrid may well be miffed. Indeed reports in Spain say they are extremely unhappy that the entire draw is being rerun. They were handed a seemingly favorable tie with Benfica before any technical snafus emerged but are now at risk of an altogether more unfavorable draw.

When will the last 16 take place?

The redrawn ties will take place in the new year with seeded teams playing the second leg at home. The first legs are scheduled for February 15,16, 22, 23, with the second legs on March 8, 9, 15, 16.