The mod Biter Hunt Group (20.0.6) caused a non-recoverable error.
Please report this error to the mod author.

Error while running event biter_hunt_group::on_tick (ID 0)
LuaGuiElement API call when LuaGuiElement was invalid.
stack traceback:
[C]: in function 'index'
__biter_hunt_group/scripts/gui.lua:69: in function 'UpdatePlayer'
biter_hunt_group/scripts/gui.lua:124: in function <biter_hunt_group/scripts/gui.lua:122>
(...tail calls...)
biter_hunt_group/scripts/packs.lua:97: in function '?'
biter_hunt_group/utility/event-scheduler.lua:84: in function <biter_hunt_group/utility/event-scheduler.lua:74>

happened to JD when he:
REMADE a new map after finding which mods i wanted installed
made a save uploaded that and mods to server
connected to server and sat there for a few more minutes (likely some default time had elapsed and mod tried to do something).

happened a second time to JD mid stream after other successful biter groups had hunted him.

I saw that before the crash there was no GUI announcing that the biters were coming soon and the error is about an invalid GUI. My suspicion is that the GUI is vanishing for some reason and my code then errors when it tries to remove it or change it?

From watching the replay it looks like he was dead 1 minute before the crash and so maybe in that case we don't create the hunt text ?

Can't find a cause of why part of the GUI vanishes, but the mod now detects it and recreates it as required.
Suspect its caused by another mod or scenario.
Prints an in-game message when its detected so I can see if a cause can be identified in future.