The mod Tank Squads (0.42.0) caused a non-recoverable error.
Please report this error to the mod author.
Error while running event tank-squads::on_nth_tick(6)
LuaEntity API call when LuaEntity was invalid.
stack traceback:
[C]: in function 'index'
__tank-squads/scripts/headquarters.lua:241: in function 'clear_path'
tank-squads/scripts/headquarters.lua:279: in function 'sweep'
tank-squads/scripts/headquarters.lua:299: in function 'tick'
tank-squads/control.lua:501: in function <tank-squads/control.lua:488>
The bug occured every time I loaded from the save so I was able to make a video:
https://youtu.be/k08Xbku5fWA
As far as I can tell it's just the mobile headquarters driving through the cliffs.
A request on the side: Can you make the mobile headquarters a possible target for escort mode? They are so slow that protecting them when traveling is very annoying as they get left behind. (If you want to, of course)
EDIT: I just noticed I misstyped "Bug Report", I'm so sorry.