Sir Charles Chaplin's studio burned down during production. This, combined with a number of major personal issues that arose during production, led to his nervous breakdown. (He spent time recovering in New York after about two-thirds of the film had been shot.)
Sir Charles Chaplin practiced tightrope walking for weeks before filming. He actually performed on a rope 40 feet in the air. However, the footage was lost when the negative was scratched during processing. The scene had to be reshot, and the footage included in the film was not as good, in Chaplin's estimation, as that which had been lost.
During production, Sir Charles Chaplin was served divorce papers by Lita Grey after two years of marriage. She was 17. She started working with Chaplin when she was 12, and he began having an affair with her soon after. They married when she was 15 after she lied about being pregnant, but she ended up having two sons during their marriage. Grey dragged his sex life into the media with sensational claims in the court documents that severely tarnished Chaplin's image. Then the IRS got involved, claiming Chaplin owed a $1 million in back taxes. He spent a good deal of time in New York and London with the print of what had been completed, trying to stave off a nervous breakdown. The stress was so great that his hair, graying when production began, went completely white by the time filming resumed and had to be dyed to match.
In October 2010, a clip from the 1928 premiere of this movie (which can be found as a bonus feature on the DVD release) was featured on several network morning shows because of speculation that it showed definitive evidence of "time travel." In the scene, a woman walking past the zebra, appears to be talking on, of all things, a cell phone. The device was later determined to be a 1924 Siemens hearing aid.