f(x) staged their performance with only four members at the 'SMTOWN Live World Tour IV' concert held at Seoul World Cup Stadium on August 15.
Krystal, Amber, Victoria, and Luna made their performance without Sulli, who began her emporary hiatus at the end of last month. An SM Entertainment representative confirmed before the concert, "Sulli won't be attending the SMTOWN concert. Only 4 members of f(x) will be on stage. We're respecting her wishes, and we plan to protect our artist by minimizing her activities and giving her time to rest."
f(x) have ended their promotions for "Red Light" on the July 20th episode of 'Inkigayo', and after that, Sulli has revealed to take a break.
There still has no word as to whether Sulli is attending the upcoming 'SMTOWN Live World Tour IV' concerts set this October in China and Japan.