Killing an npc gives you a reward issue? [Solved]

So basically I have a zombie npc and every time you kill the zombie it should give the last player that damaged it a reward, the problem is it's not doing this and I really don't have a solution. Maybe one of you guys can figure it out?

rewardmessage = game.Lighting.KillerReward

script.Parent.Zombie.Died:connect(function()
	if script.Parent.Zombie.Health == 0 then
		local killer = script.Parent.Zombie.creator
		print(killer.Value)
		local rewardclone = rewardmessage:clone()
		rewardclone.Parent = game.Players[killer.Value].PlayerGui.MainScreen
		if game.Players[killer.Value].PlayerGui.MainScreen.PlayerValues.HasCoinBooster.Value == true then
			rewardclone.CoinReward.Text = "+2 coins"
			if game.Players[killer.Value].PlayerGui.MainScreen.PlayerValues.HasXPBooster.Value == true then
				rewardclone.XPReward.Text = "+10 XP"
			else rewardclone.XPReward.Text = "+5 XP"
			end
		else
			rewardclone.CoinReward.Text = "+1 coin"
			if game.Players[killer.Value].PlayerGui.MainScreen.PlayerValues.HasXPBooster.Value == true then
				rewardclone.XPReward.Text = "+10 XP"
			else 
				rewardclone.XPReward.Text = "+5 XP"
			end
		end
	end
end)

BlueTaslem helped me but here is a simple solution to those needing help. I was trying to use a objectvalue to find a location in Players but this requires a string value and objectvalue is not a string value. To fix this all you need to do is to get the name of the value of the objectvalue... Example: objectvalue.Value.Name and then I can use this as the location!

Here is the fixed code:

rewardmessage = game.Lighting.KillerReward

script.Parent.Zombie.Died:connect(function()
	if script.Parent.Zombie.Health == 0 then
		local killer = script.Parent.Zombie.creator
		print(killer.Value.Name)
		local rewardclone = rewardmessage:clone()
		rewardclone.Parent = game.Players[killer.Value.Name].PlayerGui.MainScreen
		if game.Players[killer.Value.Name].PlayerGui.MainScreen.PlayerValues.HasCoinBooster.Value == true then
			rewardclone.CoinReward.Text = "+2 coins"
			if game.Players[killer.Value.Name].PlayerGui.MainScreen.PlayerValues.HasXPBooster.Value == true then
				rewardclone.XPReward.Text = "+10 XP"
			else rewardclone.XPReward.Text = "+5 XP"
			end
		else
			rewardclone.CoinReward.Text = "+1 coin"
			if game.Players[killer.Value.Name].PlayerGui.MainScreen.PlayerValues.HasXPBooster.Value == true then
				rewardclone.XPReward.Text = "+10 XP"
			else 
				rewardclone.XPReward.Text = "+5 XP"
			end
		end
	end
end)