No specific reason was given for the cancellation, however the show was delayed by almost 2 hours before being cancelled.
Yesterday night’s showing of Epcot Forever, scheduled for 9:00pm (U.S. time), was finally cancelled an hour and 45 minutes later due to Epcot being open until 11:00pm for Extra Magic Hours.
According to WDWNT, guests at Epcot described that the torches that surround World Showcase Lagoon never went on at 8:30pm, neither did the pre-show music.
There is no word if the cancellation of yesterday’s showing means anything for forthcoming showings. An overview of Epcot Forever can be watched below: