attempt to concatenate Instance with string line 11?

game.Players.PlayerAdded:Connect(function(player)
	player.Chatted:Connect(function(Message)
		local SplitMessage = Message:split(" ")
		if SplitMessage[1] == "/rank" then
			print("Command Is Correct")
			local NameOfPlayerToGiveRankTo = SplitMessage[2]
			local PlayerToGiveRankTo = game.Players:FindFirstChild(NameOfPlayerToGiveRankTo)
			local RankName = Message:split(NameOfPlayerToGiveRankTo)[2]
				
			PlayerToGiveRankTo.leaderstats.Rank.Value = RankName
			print(player.Name.." changed "..PlayerToGiveRankTo.."'s rank to "..RankName.."!")
		end
	end)
end)

This is the client side notification

EventsFolder.NotifySender.OnClientEvent:Connect(function(PlayerToGiveRankTo, RankName)
	wait(0.5)
	game.StarterGui:SetCore("ChatMakeSystemMessage",{
		Text = "You have changed ".. PlayerToGiveRankTo .."'s rank to ".. RankName .."!";
		Font = Enum.Font.SourceSansBold;
		Color = Color3.fromRGB(85,255,0);
		TextSize = 18;
	})
end)