I need help on a weld to connect it to a R6 model?

Error Output Code: 20:38:30.638 - Expected BasePart got Model for Weld:Part0. 20:38:30.639 - Stack Begin 20:38:30.639 - Script 'Workspace.R15_Kit.Button.LeftArm', Line 19 20:38:30.639 - Stack End

function onTouched(hit)
    if hit.Parent:findFirstChild("Humanoid") ~= nil and hit.Parent:findFirstChild("LeftArm") == nil then
        local g = script.Parent.Parent.LeftArm:clone()
        g.Parent = hit.Parent
        local C = g:GetChildren()
        for i=1, #C do
            if C[i].className == "Part" or "Union" then
                local W = Instance.new("Weld")
                W.Part0 = g.Middle
                W.Part1 = C[i]
                local CJ = CFrame.new(g.Middle.Position)
                local C0 = g.Middle.CFrame:inverse()*CJ
                local C1 = C[i].CFrame:inverse()*CJ
                W.C0 = C0
                W.C1 = C1
                W.Parent = g.Middle
            end
                local Y = Instance.new("Weld")
                Y.Part0 = hit.Parent["LeftArm"]
                Y.Part1 = g.Middle
                Y.C0 = CFrame.new(0, 0, 0)
                Y.Parent = Y.Part0
        end

        local h = g:GetChildren()
        for i = 1, # h do
            if h[i].className == "Part" or "Union" then
                h[i].Anchored = false
                h[i].CanCollide = false
            end
        end

    end

end

script.Parent.Touched:connect(onTouched)