Mariah Carey was supposed to show up to tape a segment for NBC's annual tree-lighting ceremony at the Rockefeller Center on Tuesday, but the singer failed to do so, according to the NY Daily News.

The pop star, who was supposed to tape a performance of her Christmas tracks, including "All I Want For Christmas Is You," reportedly kept network staff and crew waiting for three hours, and although she was able to arrive in time to perform on Wednesday's show, she was still called out for her "diva" behavior.

"The diva was supposed to pretape her performance of Christmas songs, like she's done before," a source for Confidenti@l stated.

The insider added, "The show is live Wednesday, but producers have learned their lesson with her over the years, and that they must pretape her. She always shows up late."

Although fans were angry they couldn't see the taping of the singer's "All I Want For Christmas Is You" performance, Mariah Carey may have actually had a legitimate reason to miss her call time. Sources reportedly told the New York Post that Carey's estranged husband Nick Cannon's legal team was to blame for the singer's absence as they had kept her occupied with custody issues.

Mariah Carey was reportedly in a hotel room that was close to the 82nd annual "Christmas in Rockefeller Center" tree-light show, but still failed to show up to pretape "All I Want For Christmas Is You" because she was arguing over custody of twins Monroe and Moroccan Scott, according to Fox News.

Carey has since apologized for the incident on Twitter.

"Last night's situation was beyond my control. I apologize to all that showed up, you know that I would never want to disappoint you," explained Carey.