This is the very low level event near Shaemoor, where bandits build two barricades across the bridge between Shaemoor and the fields.
It is possible to become stuck in one of the barricades. I have seen two ways to do this:
1. As a Guardian, use Judge’s Intervention to teleport adjacent to a bandit just behind the barricade.
2. Stand in the location of a barricade when the bandits finish building it.
Once you are stuck in the barricade, you are stuck there until you and/or other players destroy it. It is, thankfully, possible to damage the barricade while you are stuck in it…