Cannot get included lua functions

FiveM Resource Development & Modding Discussion
1

I Included a lua file in my fxmanifest.lua. Its supposed to simulate linq functions like in c#. Aside from that I tried two files but the functions in these files just wont exist in my other lua file.

client_scripts { 
    "@NativeUI/NativeUI.lua",
    "lualinq.lua", 
    "basic_client.lua",
    "menu_client.lua",
}

I have this in my resource file, but in my menu_client file I get the error “Attempt to call a nil value” when calling a function from the other file.

Can anyone help me?