"player argument must be a player object."?

--Server Script
local tool = script.Parent
local clickEvent = tool:WaitForChild("ClickEvent")
local localTrip = game.ReplicatedStorage:WaitForChild("LocalTripEvent")
local clickEventConnection
 
local function onEquip()
	clickEventConnection = clickEvent.OnServerEvent:Connect(function(player)
		local hitbox = Instance.new("Part", player.Character)
		hitbox.CanCollide = false
		hitbox.Size = Vector3.new(3,1,2)
		hitbox.CFrame = player.Character.PrimaryPart.CFrame + (player.Character.PrimaryPart.CFrame.lookVector*3 + Vector3.new(0,1,0))
		hitbox.Transparency = 0.5
		game:GetService("Debris"):AddItem(hitbox, 0.1)
		hitbox.Touched:Connect(function(part)
			if part.Parent == player.Character then return end
			local human = part.Parent:FindFirstChild("Humanoid")
			if human then
				localTrip:FireClient(human.Parent.Parent)
				hitbox:Destroy()
			else
				hitbox:Destroy()
			end
		end)
	end)
end
 
local function onUnequip()
	clickEventConnection:Disconnect()
end
 
tool.Equipped:Connect(onEquip)
tool.Unequipped:Connect(onUnequip)

--LocalScript
local tool = script.Parent
local player = game.Players.LocalPlayer
repeat wait() until player.Character
local humanoid = player.Character:WaitForChild("Humanoid")
local anim = tool:WaitForChild("PushAnim")
local number = 6
local debounce = false

local clickEvent = tool:WaitForChild("ClickEvent")
local tripEvent = game.ReplicatedStorage:WaitForChild("LocalTripEvent")
 
local function onActivate()
	if debounce then return end
	debounce = true
	local animtrack = player.Character.Humanoid:LoadAnimation(tool.PushAnim)
		animtrack.Priority = Enum.AnimationPriority.Action
		animtrack:Play()
		animtrack.KeyframeReached:Connect(function(keyframeName)
			if keyframeName == "Push" then
				clickEvent:FireServer()
			end
		end)
	for i=1,5 do
		number = number - 1
		tool.Name = number
		wait(1)
	end
	tool.Name = "Push"
	number = 6
	debounce = false
end
 
tool.Activated:Connect(onActivate)
tripEvent.OnClientEvent:Connect(function()
	humanoid.Parent.HumanoidRootPart.Velocity = humanoid.Parent.HumanoidRootPart.CFrame.lookVector * -50
	humanoid:ChangeState(Enum.HumanoidStateType.FallingDown)
	print("success")
end)

Everytime I run this pushing script, the FireClient() (line 19) sends a error "player argument must be a player object". How do I fix this?