YOUR DEVICE WAS DEAUTHORIZED BY SOMEONE ELSE WHO IS USING THE SAME TICKET THAT YOU ARE USING.
Are you the one who did this? If so, watch from the device/browser you just launched your ticket on. If you want to watch it here instead, relaunch your original LiveStream ticket email to access the stream.
If you shared your ticket with a friend, or they shared their ticket with you, you can't both use the same ticket. You can relaunch your original LiveStream ticket, but if your friend tries to use it at the same time as you, it will kick you out of the stream.
If you purchased multiple LiveStream tickets make sure you and your friends are each only using 1 of the tickets in your order at any one time. Multiple tickets in an order will be labeled uniquely, for example: Ticket 1 of 3, Ticket 2 of 3, Ticket 3 of 3.