Workspace.A:10: attempt to index field '?' (a nil value)?

I'd tried figuring out this problem on my own, I just ran out of solutions. Here is the code. The error happened on line 10. No locals are used because they aren't allowed in the game I'm able to test them in.

function1 = function()

    for i, v in pairs(game.Workspace.Map.Intro._IntroA:GetChildren()) do 

    game:GetService('TweenService'):Create(game.Workspace.Map.Intro._IntroA:GetChildren()[v],
        TweenInfo.new(1.5,Enum.EasingStyle.Back,Enum.EasingDirection.Out,0,false,3),
    {CFrame = game.Workspace.Map.Intro._IntroA:GetChildren()[v].CFrame + Vector3.new(-6.25,0,0)}):Play()


    end
end


wait(3)
function1()