he mod Laser Fence (1.1.3) caused a non-recoverable error.
Please report this error to the mod author.

Error while running event laserfence::on_tick (ID 0)
LuaEntity API call when LuaEntity was invalid.
stack traceback:
[C]: in function 'index'
__laserfence/scripts/CnC_Walls.lua:285: in function 'CnC_SonicWall_OnTick'
laserfence/control.lua:107: in function <laserfence/control.lua:105>

I couldn't replicate this specific issue, but I've added some additional safety checks in 1.1.4 to prevent this going forward.