A representative from LOEN Entertainment tweeted this incident and also 投稿されました a picture of people trying to fix the door and get IU(アイユー) out of the room. Luckily it didn’t take too long to get IU(アイユー) out of it and she managed to perform well in M!Countdown.
Source: wowkeren.com
写真 Credit: showasia.ru, kapanlagi.com