The mod Construction Drones (0.5.3) caused a non-recoverable error.
Please report this error to the mod author.
Error while running event Construction_Drones::on_tick (ID 0)
invalid key to 'next'
stack traceback:
[C]: in function 'next'
Construction_Drones/script/construction_drone.lua:656: in function 'check_list'
Construction_Drones/script/construction_drone.lua:1131: in function 'check_deconstruction_lists'
Construction_Drones/script/construction_drone.lua:1330: in function 'handler'
core/lualib/event_handler.lua:47: in function <core/lualib/event_handler.lua:45>