Humanoid is not a valid Enum Item. Why, and how do I fix this?

I am doing a Kill for XP script and it seems that this code will not work from lines 21 to 26.

local DS = game:GetService("DataStoreService")
local XPStore = DS:GetOrderedDataStore("XP")

game.Players.PlayerAdded:Connect(function(player)
    local leaderstats = Instance.new("Folder", player)
    leaderstats.Name = "leaderstats"

    local XP = Instance.new("IntValue", leaderstats)
    XP.Name = "XP"

    pcall(function()
        local XPVal = XPStore:GetAsync(player.UserId)
        if XPVal then
            XP.Value = XPVal
        end
    end)

    player.CharacterAdded:Connect(function(Character)
        local humanoid = Character:FindFirstChild("Humanoid")
        if humanoid then
            if humanoid.RigType == Enum.humanoid.HumanoidRigType.R6 then
                local clone = game.ServerStorage:WaitForChild("R6Sword")
                clone.Parent = player.Character
            elseif humanoid.RigType == Enum.humanoid.HumanoidRigType.R15 then
                local clone = game.ServerStorage:WaitForChild("R15Sword")
                clone.Parent = player.Character
        Character.humanoid.Died:Connect(function()
            local tag = Character.Humanoid:FindFirstChild("creator")
            if tag == nil then
                local player = tag.Value
                local XP = 10
                local leaderstats = player:WaitForChild(leaderstats)
                leaderstats.XP.Value = leaderstats.XP.Value + XP
            end
        end)
            end
        end
    end)
end)

game.Players.PlayerRemoving:Connect(function(player)
    pcall(function()
        if player:FindFirstChild("leaderstats") and player.leaderstats:FindFirstChild("XP") and player.leaderstats.XP.Value > 0 then
            XPStore:SetAsync(player.UserId, player.leaderstats.XP.Value)
        end
    end)
end)

I don't know why this happened but I guess. Any help?