A trigger that executes when the timeline of an object starts or ends (see example below) may fire more than once if you use the seekbar to move back and forth along the slide’s timeline.
Depending on the action being triggered, this could cause undesirable results. If you do not want this type of trigger to fire more than once, disable the seekbar. Here's how:
For an individual slide
To remove the Seekbar from a single slide (or series of slides), uncheck the Seekbar box in the slide properties.
For the entire course
To remove the Seekbar from the entire course, uncheck the Seekbar box in Player > Features.