"Empire" co-creator Lee Daniels admitted Friday the top-rated hip-hop soap opera had lost its way after a record-breaking first season -- but vowed the US show was back to its best.

Broadcast television's number one program hit a high of almost 18 million viewers in its season one finale but episodes in the new season have dropped as low as nine million with criticism over storylines.

"What happened was growing pains," Daniels told the PaleyFest TV festival in Los Angeles, agreeing with host Kevin Frazier that the show had gone "a little left".

"I think it would have happened to any show and I think that, though we still remained number one, we were learning, you know?"

"Sometimes you don't feel like it's enough, that these people, these wonderfully talented actors, are enough," he added, explaining the introduction of new characters that had not worked.

Critics have been scathing about some of the early episodes in the second season, which debuted in September last year, complaining that the show had fallen off creatively.

"Nothing interesting is happening, and what is happening isn't even happening in a fun or surprising way," said entertainment website The AV Club.

"The music is hit-and-miss, and the show is grossly overpopulated with characters who serve no purpose."

But Daniels told the audience at Hollywood's Dolby Theatre the show's development was a process of "trial and error," adding, to a large cheer: "At the end of the day, well we came back."

"We've really been learning about everybody and trying things out. Otherwise, how do you make greatness without testing it?" he said.

Several cast and crew joined Daniels on stage for a question and answer session after a screening of the first new episode after the mid-season break, due to air on March 30.

Trai Byers, who plays Andre Lyon in the prime time Fox show, denied persistent rumors that he is about to quit, while Daniels took a swipe at Republican presidential hopeful Donald Trump.

"I don't have time to deal with racism," he said to a question about Hollywood's lack of racial diversity, highlighted by this year's all-white Oscar nominations in the acting categories.

"I thought, yes, am I delusional to say that there's not racism in America? Look at... Donald Trump."

PaleyFest, which runs until March 20, features exclusive screenings and panel sessions with the cast and crew of a number of top shows, including "Better Call Saul," "Scandal" and "Fear the Walking Dead."