This is a recurring bug among PTR testers venturing into the Antoran Wastes in build 24633. First, don’t go near the bridge marked in the map below with an orange circle. That bridge leads to the Antorus raid zone, and it is crystal clear Blizzard doesn’t want you in that area. There is no giant Infernal gazing upon you as a fair warning that you will be instantly killed.
Instead, fel balls will be hurled from the lake at your character until you are killed. Divine shield won’t protect you. Even if you make it past the bridge after several deaths, I was told past the bridge has invisible walls that will also kill you.
The bug is that because this area is off-limits, you will be sent to a graveyard at the Shaper’s Rise (by the Spirit Crucible) which is not operational at the moment. Your ghost will fall through the sky beneath the ground, and you will be disconnected from the game. No work around here. You will load the game, the character ghost will start falling from the sky beneath the graveyard, and you will get disconnected. Rinse and repeat to no avail.
So learn from this, and steer away from this bridge or avoid dying in the area of the bridge or in the north. The southern graveyard works fine if you die in that area.
I have been a technical alpha, beta, and PTR tester since 2004. If you are wondering, this issue will be resolved at some point. Either in the next build or any time soon. In past experiences where my ghost falls through the world, all characters have been resurrected and moved by the developers to another location. It will just take some time. Try again everyday to find out if it’s been fixed.