Officers said they determined after an hour that a mysterious box left on a bench outside a sports store was a DVD player.
Another case of aging technology caused alarm last week in Vancouver.
Metro Vancouver's SeaBus was shut down for nearly four hours after an item was found under one of the ferry's seats.
It turned out to be a Walkman.
There were security concerns about Edmonton's mega-mall after a video was released last month from a terrorist group threatening an attack on the shopping centre and others around the world.
Police have said there is no evidence of an imminent threat and the mall is safe.