Guild Wars 2

I have attempted to complete this part of the story on my level 50 necromancer 3 times today all got stuck at the exact same area.
It happens just after the cutscene of the dragon appearing and smashing the wall, the npcs then call for a retreat but the objectives don’t update.

The following screenshot is the result of my 3rd attempt to complete it, and just leaving the game open for 20 minutes.

Try going near the dragon. This happened to me before too, so I ran towards the dragon until the new objective appeared.

I can confirm what Germmar said. Approaching the broken wall will move things along.

Yep. Approach the broken wall and the dragon should use his breath attack (that inflicts Fear on you). This triggers the next phase of the story.

Note that the dragon’s breath has a cooldown, and he uses it immediately after when he first breaks the wall. So if you are near the wall and he’s not using it, hang around there for a while until it comes off cooldown and he’ll use it again.