The plot has thickened in the dispute reportedly brewing between Paramount Network and Kevin Costner over the future of “Yellowstone.”

On Saturday, “Yellowstone” star and executive producer Costner, co-creator Taylor Sheridan and several other key cast members did not attend the Paley Center for Media’s annual PaleyFest event in Los Angeles as originally scheduled. The no-show occurred nearly two months after rumors surfaced that Paramount Network was making moves to end the popular period drama amid a disagreement with Costner.

Costner and Sheridan were expected to anchor PaleyFest’s “Yellowstone” panel alongside executive producer David Glasser, as well as cast members Kelly Reilly, Cole Hauser, Luke Grimes, Kelsey Asbille, Wes Bentley, Gil Birmingham and Jacki Weaver.

None of the previously confirmed talent participated in the panel, which instead featured cast members Mo Brings Plenty, Dawn Olivieri, Josh Lucas and Wendy Moniz. Keith Cox, president of development at Paramount Network, was also present for the discussion, moderated by Deadline’s Lynette Rice.

According to Deadline, a spokesperson for the Paley Center told stunned fans in the audience that the original lineup couldn’t make it to the event because of “scheduling conflicts.”

Paramount Network did not immediately respond Sunday to The Times’ request for comment.

On Twitter, “Yellowstone” fans who purchased tickets to this year’s PaleyFest complained about the sudden programming change. One “super disappointed” attendee reported that “people were walking out” of the Dolby Theater when it became clear that the situation unfolding was not an April Fools’ prank.

“Will there be refunds for #yellowstone #PaleyFest we drove two hours to the cast you said would be here,” tweeted @james79766926. “What a joke and rip off.”

“No slight to the actors who were there, but @paleycenter should offer refunds for the @Yellowstone tonight program,” echoed @seaninthemiddle.“Not a single person, not one, who was listed to be there was actually there.”

“I want a refund #PaleyFest #yellowstone utah to California with no main cast @DolbyTheatre Hollywood,” tweeted @Sylvia00076212. “The cost of flying out, staying at a hotel and eating was not worth the show. … I’m low income and I saved and worked really hard to be here.”

The Times confirmed Sunday that PaleyFest attendees can email [email protected] with questions, comments and refund requests.

In February, Deadline reported that Paramount Network was scheming to conclude “Yellowstone” and launch another spinoff starring Matthew McConaughey. The modern western already boasts two prequel series, “1883” and “1923.”

According to the report, Paramount Network apparently made the decision to cancel “Yellowstone” after Costner raised concerns about the series’ filming schedule and the studio declined the actor’s “proposal” to alter it.

However, a source close to the production previously refuted that narrative and assured The Times that “Yellowstone” would move forward.

“We have no news to report. Kevin Costner is a big part of Yellowstone and we hope that’s the case for a long time to come,” a Paramount Network spokesperson said in a February statement to The Times.

“Thanks to the brilliant mind of Taylor Sheridan, we are always working on franchise expansions of this incredible world he has built.”

Weeks later, an attorney for Costner denied rumors that the “Yellowstone” team was frustrated with his client for allegedly holding up the production by limiting his shooting availability.

“It’s ridiculous — and anyone suggesting it shouldn’t be believed for one second,” Costner’s rep, Marty Singer, said in a February statement to The Times.

“As everyone who knows anything about Kevin is well aware, he is incredibly passionate about the show and has always gone way above and beyond to ensure its success.”

At Saturday’s PaleyFest panel, Cox hailed Costner as “our star, the face of our show, and the executive producer” and reiterated that the network is “very confident he will continue with the show.” He also claimed that fans would “soon” receive a production update on “Season 5,” which was supposed to finish filming last year but has since been stalled.

Times staff writers Alexandra Del Rosario and Nardine Saad contributed to this report.