Ja Rule was Fyre’s famous face, but at the center of the controversy is Mr. McFarland, a brash, 25-year-old entrepreneur with a gift for networking and buzzy social media. In his short career, he has persuaded people, over and over, to buy or invest in whatever he was selling, leaving behind a trail of aggrieved customers and business partners. He could be the Wolf of Wall Street for the selfie set, or Gatsby run through an Instagram filter.

Mr. McFarland and his lawyers declined to address specific allegations. But in a statement, he said: “I cannot emphasize enough how sorry I am that we fell short of our goal,” adding, “I’m committed to, and working actively to, find a way to make this right, not just for investors but for those who planned to attend.”

Stacey Richman, a lawyer for Ja Rule, said that he “would never participate in anything fraudulent; it’s simply not in his DNA.”

But interviews with more than two dozen people associated with Mr. McFarland or the festival, many of whom requested anonymity because of pending legal issues, turned up few who were surprised by the ruins in the Bahamas and beyond.