Attemp to index nil with value. How do i fix this?

the problem is on line 13

local plrs = game:GetService("Players")

local plr = plrs.LocalPlayer

for i,v in pairs (workspace.Spawns:GetChildren()) do
	if v:IsA("Part") then
		v.Touched:Connect(function(hit)
			if hit.Parent:FindFirstChild("Humanoid") then
				local player = game.Players:GetPlayerFromCharacter(hit.Parent)
				if tonumber (v.Name) > player.leaderstats.Stage.Value then
					if player.leaderstats.Stage.Value ~= tonumber(v.Name) then
						player.leaderstats.Stage.Value = tonumber(v.Name)
						plr.Gems.Value = plr.Gems.Value + plr.Stage.Value
					end
				end
			end
		end)
	end
end

local respawnDDelay = 0

game.Players.CharacterAutoLoads = false

game.Players.PlayerAdded:Connect(function(plr)
	
	plr.CharacterAdded:Connect(function(char)
		local hum = char:FindFirstChild("Humanoid")
		if hum then
			hum.Died:Connect(function()
				wait(respawnDDelay)
				plr:LoadCharacter()
				plr.Character:FindFirstChild("HumanoidRootPart").CFrame = workspace.Spawns[plr.leaderstats.Stage.Value].CFrame
			end)
		end
	end)
	plr:LoadCharacter()
end)

In the beginning of your code you set the player "plr" to "plrs.LocalPlayer". I'm assuming this is in a server script and "local player" can't be used in a server script so it would be nil which is why using .Value on Gems would also be nil and create your error.

https://developer.roblox.com/en-us/api-reference/property/Players/LocalPlayer

It might be better to instead make it a function and pass the player to it from when the player is added, I could be wrong though on how to get the player.

local respawnDDelay = 0

game.Players.CharacterAutoLoads = false


game.Players.PlayerAdded:Connect(function(plr)
	plr.CharacterAdded:Connect(function(char)
        local hum = char:FindFirstChild("Humanoid")
        if hum then
            hum.Died:Connect(function()
                wait(respawnDDelay)
                plr:LoadCharacter()
                plr.Character:FindFirstChild("HumanoidRootPart").CFrame = workspace.Spawns[plr.leaderstats.Stage.Value].CFrame
            end)
        end
    end)
    plr:LoadCharacter()

	for i,v in pairs (workspace.Spawns:GetChildren()) do
	    if v:IsA("Part") then
	        v.Touched:Connect(function(hit)
	            if hit.Parent:FindFirstChild("Humanoid") then
	                local player = game.Players:GetPlayerFromCharacter(hit.Parent)
	                if tonumber (v.Name) > player.leaderstats.Stage.Value then
	                    if player.leaderstats.Stage.Value ~= tonumber(v.Name) then
	                        player.leaderstats.Stage.Value = tonumber(v.Name)
	                        plr.Gems.Value = plr.Gems.Value + plr.Stage.Value
	                    end
	                end
	            end
	        end)
	    end
	end
end)