Why do I get this error?: "attempt to index nil with 'GetDescendants'"

I think tables might require brackets like this {} but not sure whats wrong.

Would recommend not doing

local char = player.Character or player.CharacterAdded:Wait()

Instead do

local Players = game:GetService("Players")

Players.PlayerAdded:Connect(function(player)
    print(player.Name .. " joined the game!")
    print(player.Name .. " joined the game!")
    player.CharacterAdded:Connect(function(char)
        print(char)
        print(player)
        print(player.Character)
        print("Test Test TEst")
        local function Getacessory(char)
            local descendants = char:GetDescendants()
            for index, descendant in pairs(descendants) do
                if descendant:IsA("Accessory") then
                    print(descendant.Name)
                end
            end
        end
        Getacessory()
    end)
end)

I think its because you told the function to except a parameter Char, but when you fired etacessory() you didn't send a parameter and because of the scope,it trys to use the char that was passed to the function not the one outside of it, but you never actually passed anything to char when you fired Getacessory() so char is nill.

i think you can just remove the parameter when making the function

so instead of this its:

local function Getacessory(char)

its this:

local function Getacessory()

or you could pass char when calling the function like this:

Getacessory(Char)