Error? Attempt to concatenate (NON table)

ANSWERED: https://gyazo.com/6a99c74e7868f9b4e6225f3edb678837

QUESTION QUESTION QUESTION

Alright, so... My script is erroring, and in the error box it's saying:

What is the error? (Added because I need to have a question mark)

--[[
1x..3
20:03:55.332 - ServerScriptService.Main:28: attempt to concatenate local 'g' (a nil value)
20:03:55.333 - Stack Begin
20:03:55.333 - Script 'ServerScriptService.Main', Line 28 - global selectrandom
20:03:55.333 - Script 'ServerScriptService.Main', Line 38
20:03:55.333 - Stack End
]]--

Note, the script I will provide is NOT the entire script, but will be all that is needed...

function getnextpos(Table)
    local num = #Table
    local toreturn = num+1
    return(toreturn)
end

function a(z,selections)
        local x = math.random(1,#z)
        print("1x.."..x)
        for index,returned in ipairs(selections) do
            print(x)
            if x == returned then
                local y = a()
                print("y.."..y)
                return y
            end
            print("x.."..x)
            return x
        end
end

function selectrandom(location,count)
    local z = location:GetChildren()
    local selections = {}
    for i = 1,count do
        local val
        local g = a(z,selections)
        print("g = "..g)
        table.insert(selections,getnextpos(selections),g)
    end
    return(selections)
end

The issue, as I understand it, is NOT with my table, but with my returned variables, and functions I tried using a local function, but since it did not work, tried to move it out to a normal function, which also did not work. DO not worry about shortening any code you give me, as I can do that myself.

How should I fix this error?????? (Added because I "Need to have a question mark".)

Thanks, Taryo. ;)