Same thing happened on my first attempt to cross over to get to forge, long animation of death. I had not yet learned the recipes yet so wonder if that is the issue? Anyway once I respawned back at base I went back and this time learned the recipes then walked slowly accross that grill to the forge with no problem. Weird…but has to be a bug?
Sorry you had trouble at the forge. I did too my first time. I’ve since come to see it as a feature, not a bug. Now, I jump onto the back of the platform, close to the forge fire, from either side. The NPCs try to attack me by running across the grate in the middle. They usually die. Just jump carefully and you will be fine.