"attempt to index field 'darkvision' (a nil value)" problem

[JiRo.0]

Hello! I wanted to make a character that would have the same night vision system like Charlie mod. I don't really know a lot about programming so I was looking into different mods and picking out some parts of codes. At first everything was fine, I solved every problem I could, but in the end I don't know how to solve this one: "[string ".../scripts/perfabs/alek.lua"]:129: attempt to index field 'darkvision' (a nil value)"

I've looked into line 129 and this is what I've got:

I don't understand what's the problem and how to solve it, so can anybody explain what I can do about it and why something like this happend? Thanks!

 

Edited February 24, 2023 by JiRo.0