A frightening showing at the box office this weekend featured five disappointments—including two of the biggest flops in history.

“Steve Jobs,” “The Last Witch Hunter,” “Paranormal Activity: The Ghost Dimension,” “Rock the Kasbah” and “Jem and the Holograms” all fell short, with only “Witch Hunter” cracking $10 million. “Kasbah” and “Jem” now rank among the worst openings of all time, and “Paranormal” missed expectations after weeks of anticipation over its divisive distribution strategy.

Instead,...