1 is not a valid member of Players? It's meant to return a Player?

It needs to find all the players so it can change the Properties of a PlayerGui. Here's my script:

script.Parent.MouseButton1Click:Connect(function()
	local Slot = script.Parent.Parent.Parent.Parent:GetChildren()[math.random(1,#script.Parent.Parent.Parent.Parent:GetChildren())]
	if Slot.Name == "Slot1" then
		if Slot.Visible == false then
			script.Parent.Parent.Visible = false
			local players = game.Players:GetChildren()
			for i = 1,#players do
				game.Players[i].PlayerGui.MainGui.Missions[Slot.Name].Visible = true
				game.Players[i].PlayerGui.MainGui.Missions[Slot.Name].Difficulty.Text = script.Parent.Parent.Vals.Difficulty.Value
				game.Players[i].PlayerGui.MainGui.Missions[Slot.Name].Host.Text = script.Parent.Parent.Parent.Parent.Parent.Parent.Parent.Name
				game.Players[i].PlayerGui.MainGui.Missions[Slot.Name].Mission.Text = script.Parent.Parent.Vals.Mission.Value
				game.Players[i].PlayerGui.MainGui.Missions[Slot.Name].Players.Text = "Players: 1/4"
				game.Players[i].PlayerGui.MainGui.Missions[Slot.Name].Host.HostName.Value = script.Parent.Parent.Parent.Parent.Parent.Parent.Parent.Name
				game.StarterGui.MainGui.Missions[Slot.Name].Visible = true
				game.StarterGui.MainGui.Missions[Slot.Name].Difficulty.Text = script.Parent.Parent.Vals.Difficulty.Value
				game.StarterGui.MainGui.Missions[Slot.Name].Host.Text = script.Parent.Parent.Parent.Parent.Parent.Parent.Parent.Name
				game.StarterGui.MainGui.Missions[Slot.Name].Mission.Text = script.Parent.Parent.Vals.Mission.Value
				game.StarterGui.MainGui.Missions[Slot.Name].Players.Text = "Players: 1/4"
				game.StarterGui.MainGui.Missions[Slot.Name].Host.HostName.Value = script.Parent.Parent.Parent.Parent.Parent.Parent.Parent.Name
			end
		else
			script.Parent.Text = "Error Occured! Try again!"
			wait(2)
			script.Parent.Text = "Ready!"
		end
	else
		script.Parent.Text = "Error Occured! Try again!"
		wait(2)
		script.Parent.Text = "Ready!"
	end
end)

Anything wrong with it?