Lionsgate hoped to end its presentation to theater owners at CinemaCon with a big bang — a screening of “Now You See Me 2.”

But roughly 15 minutes into the tale of a team of illusionists, the audience at the Colosseum in Caesars Palace was told to leave the theater, with security personnel citing “technical difficulties.” A CinemaCon staffer confirmed that, after the discovery of an unattended backpack, the theater was evacuated.

“Out of caution for the delegates and attendees, a potential threat had to be taken seriously,” said John Fithian, head of the National Association of Theatre Owners, the group behind CinemaCon, in a statement. “By the time we determined it was not a threat it was too late to restart the movie.”

A spokesperson with the Las Vegas Police Department said authorities had been called in due to a “suspicious package,” but said the situation was determined safe at 3:35 p.m.

“Now You See Me 2” stars Jesse Eisenberg, Mark Ruffalo, Woody Harrelson, Dave Franco, Michael Caine, Morgan Freeman, and Daniel Radcliffe. It hits theaters on June 10, 2016.