Parent property locked, current parent:NULL?

local human = script.Parent:WaitForChild("Humanoid")
local center = game.Workspace.CentralPart
local debounce = false
while wait(2.5) do
    local random = Random.new()
local random2 = Random.new()
local range = random:NextInteger(-50, 50)
local range2 = random2:NextInteger(-50, 50)
    local wave = game.ReplicatedStorage.Ring:Clone()
    human.Jump = true
    human:MoveTo(center.Position + Vector3.new(range, 0, range2))
    human.MoveToFinished:Connect(function()
        if human.Jump == false then
        wave.Position = Vector3.new(script.Parent:WaitForChild("Torso").Position.X, 80.28, script.Parent:WaitForChild("Torso").Position.Z)
        wave.Parent = workspace
        script.Parent.Sound:Play()
        wave.Touched:Connect(function(hit)
            local hithum = hit.Parent:FindFirstChild("Humanoid")
            if hithum then
                if hithum ~= human and debounce == false then
                    debounce = true
                    hithum.Health = hithum.Health - 60
                    wait(1)
                    debounce = false
        end
    end
end)
        for i = 1, 50 do
            wave.Size = wave.Size + Vector3.new(3, 0, 3)
            wait()
        end
        end
        wave:Destroy()
    end)
end

Defining the variable wave before the movetofinished event would result in the wave getting deleted, but the next one would have one more than the previous cycle. The script works as intended now, but it outputs the error "Parent property of ring locked, current parent:NULL, new parent: Workspace.