[0.17.9] Scenario exits with error when completing task

[JoshuaCF]

I completed the task in the scenario where it requested that the player mine 9 coal and have 5 in the inventory. Directly before completing the task I took a single piece of coal from the fuel slot of the burner drill and added to my inventory almost right when the burner drill produced another piece of coal. I'm not sure that information is relevant, but better safe than sorry. About a second or two later, as I was walking away from the drill, the scenario froze and an error popped up.

Copy-pasted contents of the error:

Code: Select all

The scenario level caused a non-recoverable error.
Please report this error to the scenario author.

Error while running event level::on_tick (ID 0)
__base__/lualib/compi.lua:97: bad argument #1 to 'pairs' (table expected, got nil)
stack traceback:
	[C]: in function 'pairs'
	__base__/lualib/compi.lua:97: in function 'stand_next_to'
	__base__/lualib/npe/helper-branches.lua:683: in function 'init'
	...m/steamapps/common/Factorio/data/core/lualib/story_2.lua:231: in function 'jump_to_node'
	...m/steamapps/common/Factorio/data/core/lualib/story_2.lua:196: in function 'update'
	__base__/lualib/npe/helper_story.lua:40: in function '?'
	__base__/lualib/event_handler.lua:7: in function <__base__/lualib/event_handler.lua:4>

(I don't know if adding the exception info to a code block is what I'm supposed to do, but it feels right)