It means you’ll have either an incomplete view or something will be in your line of sight because of the position of the seats — like a pole, speakers or the sound board — and you won’t be able to see the entire stage. Don’t worry, obstructed view tickets are clearly labeled as such at time of purchase. You may see other labels like No Stage View, Video View and Listening Only indicate that the seats have no view of the stage.
The Event Organizer makes these tickets available because for many fans the view isn't a problem. If you purchased obstructed view tickets in error, contact Fan Support.