Kick Command breaking due to a nil value?

The issue was that since you're using the admin tutorial here, it has this line in the "ParseMessage" function. What is does is that it uses string.lower to the message, causing the entire thing to become lowercase. Because of this, the kick command processed the usernames as lowercase therefore not finding any players.

local Commands = {}
local Prefix = "!"

local function ParseMessage(Player,Message)
	local PrefixMatch = string.match(Message,"^"..Prefix)
	
	if PrefixMatch then
		Message = string.gsub(Message,PrefixMatch,"",1)
		local Arguments = {}
		
		for Argument in string.gmatch(Message,"[^%s]+") do
			table.insert(Arguments,Argument)
			print(Argument)
		end
		
		local CommandName = Arguments[1]
		table.remove(Arguments,1)
		local CommandFunc = Commands[CommandName]
		
		if CommandFunc ~= nil then
			CommandFunc(Player,Arguments)
		end
	end
end

Commands.kick = function(Sender, Arguments)
    local Message = table.concat(Arguments, " ")
    if (Arguments[1] == nil) then return end
    local userPlayer = Arguments[

    local reason = Arguments[2];
    if (Arguments[2] == nil) then
        reason = "No reason provided."
    end
    local findPlayer = game:GetService("Players"):FindFirstChild(userPlayer)
    if findPlayer then
	  findPlayer:Kick(reason)
    else
	  warn("Player not found.")
    end
end

game.Players.PlayerAdded:Connect(function(plr)
	plr.Chatted:Connect(function(Message)
		ParseMessage(plr,Message)	
	end)
end)

I modified the code from the tutorial a little bit. Make sure to accept my answer if its right!