Mariah Carey suffered through a performance train wreck in Times Square on New Year’s Eve as malfunctions left her at a loss vocally during her hit song “Emotions,” struggling to reach notes and to sync the lyrics and music.

The trouble continued when she gave up on another of her best-known numbers, “We Belong Together,” while a recording of the song continued to play, a confirmation that she had been lip-syncing.

But on Sunday, a dispute erupted between Ms. Carey’s representatives and producers of ABC’s “Dick Clark’s New Year’s Rockin’ Eve With Ryan Seacrest,” on which the singer was performing.

Ms. Carey’s manager, Stella Bulochnikov, charged that the show’s producers had been aware of technical problems but did not fix them — and chose to continue showing Ms. Carey’s messy performance “to get ratings.”