What really happened. Kelly Reilly revealed why she missed Yellowstone's PaleyFest panel after speculation about drama behind the scenes. The Flight actress, 45, responded to a fan who asked why she missed the event in an Instagram comment on Sunday, April 30. "Question: why didn’t you show up at PaleyFest?" asked the social media user. "I was filming in the UK at the time, and let them know in January I wouldn’t be able to attend," Reilly replied. "I was sorry to hear my name was still on the list of attendees, as it is unfair to our fans. Xx." The conversation took place in the comments section of Reilly's latest post, which showed her posing with Succession star Brian Cox. "Working with this legend is no fun at all," she quipped alongside two selfies taken with the Golden Globe winner, 76. Kelly Reilly at the Comedy Central, Paramount Network and TV Land Press Day MediaPunch/Shutterstock Last month, Reilly and her Yellowstone costars made headlines when they were absent from the Paramount Network drama's appearance at the Los Angeles festival. Kevin Costner, Cole Hauser, Luke Grimes, Kelsey Asbille, Wes Bentley, Gil Birmingham and Jacki Weaver were all scheduled to attend along with Reilly and showrunner Taylor Sheridan, but none of them were present for the April 1 event. Their costars Josh Lucas, Wendy Moniz, Mo Brings Plenty and Dawn Olivieri ultimately filled in, and press was notified 30 minutes before the red carpet began. Kevin Costner as John Dutton and Kelly Reilly as Beth Dutton in 'Yellowstone' Danno Nell/Paramount/Kobal/Shutterstock The shakeup came amid rumors that the show's future is up in the air following the midseason finale in January. Season 5's second half was scheduled to air this summer, but cast members have since confirmed that production hasn't actually started on the new episodes. In February, Deadline reported that Paramount Network was considering wrapping up Yellowstone and moving to a spinoff series centered around Matthew McConaughey amid scheduling conflicts with Costner, 68. The network denied the report at the time, but last month, Paramount Media Networks president and CEO Chris McCarthy confirmed that the Interstellar actor, 53, would indeed lead his own spinoff regardless of what happens with the original. After the main cast missed PaleyFest, an insider exclusively told Us Weekly that "ongoing issues" between Costner and Sheridan, 52, caused the last-minute cancelation. "It’s been an ongoing power play between them," the source explained. “Kevin didn’t want to come across as unauthentic and he would have if he was forced to dodge uncomfortable questions about their working relationship. It seemed like a lose-lose situation for him. It just wasn’t worth it to Kevin.” As for what's going on with the second half of season 5, the show's stars have said they don't even know when filming will start. "I'm planning on getting an update today," Lainey Wilson, who plays Abby, told Entertainment Tonight on Sunday. "It's wild." Lainey Wilson at the Billboard Women in Music Awards Chelsea Lauren/Shutterstock The country singer, 30, added that her time on the cowboy-centered drama has taught her that the "TV business is even crazier" than the music industry. "Like, just tell me when, man," she added. "Yeah, I have no clue what's going on. ... I'm waiting on that phone call." Moniz, 54, told Us last month that she knows Sheridan is writing the new episodes. "I’m along for this ride for as long as it goes. That’s what I can tell you. It’s just been a dream job," the Betrayal alum, who plays Lynelle Perry, explained at PaleyFest, adding that she has "no news" about Costner's future with Yellowstone. "We’re all just, you know, finding out what everyone else is finding out as it’s going. I’m excited to get back to work.” Her costar Brings Plenty, 53, was similarly circumspect about the drama, telling Us that he had "no answers" about Costner's return or the show's future. "I don’t even know what’s going on and I just stay in my own lane,” the Hell on Wheels veteran said in April. “I have a great deal of respect for Kevin and who he is and what he does and everyone else. And so I just mind my own business.” Lucas, 51, who appears as the younger version of Costner's character, John Dutton, theorized that Sheridan and the Dances With Wolves director feel a big "responsibility" to get Yellowstone right. "[They] are putting a lot of crazy love and pressure on each other and the show to make something that people love," the Sweet Home Alabama star told Us at PaleyFest. "There’s a reason why people love it.”