Thank you, I had already been trying to use the onevent function but I'm still having issues.
require "defines"

game.onevent(defines.events.onbuiltentity, function(event)
if event.createdentity.type == "enemy" and game.darkness > 0.5 then
game.createentity{name = "zombie", position= game.entity ...

Assuming your tech name is right, maybe check your language settings to make sure its set to English (you already probably know) and make sure your directory is correct.
"__mod-name__\locale\en".
Also i don't know if it would effect anything but "long range defence" in the description might be ...

I need help reading the darkness value on a unit spawner so I can disable spawning in the day. I understand that darkness is a read only property but I dont understand how to use it properly yet. result_units =
(function()
local res = {}
if game.entity.darkness > 0.5 then
end
res[1] = {"1", {{0 ...