Player parameter happens to not work on RemoteEvent?

Hello. I currently have a GUI Text Button set up to toggle a ForceField on a player's character. Because I am using Filtering Enabled (or Experimental Mode is off), i must use a RemoteEvent. I have a LocalScript set up to get input from the button and change a few GUI elements. The LocalScript is only capable of changing the GUI elements and not the player's ForceField. I use the FireServer() function to call a listener in a Server Script. On the Server Script, I have a variable defining the player's character. The first default parameter is the player associated with the client that sent the function. All player instances have a Character property, but for some reason it doesn't work. The code in the Server and Local Scripts are below. I also attached an image link to the setup I have. Setup Image Link

-- Server Script
local event = script.Parent:WaitForChild("RemoteEvent")

event.OnServerEvent:Connect(function(player)
    local char = player.Character
    local forcefield = char:FindFirstChild("ForceField")
    if forcefield then
        forcefield:Destroy()
    else
        c = Instance.new("ForceField")
        c.Parent = char
    end
end)

-- Local Script
local event = script.Parent:WaitForChild("RemoteEvent")
local button = script.Parent
local bg = script.Parent.Parent

local function forcefieldEvent()
    local player = game.Players.LocalPlayer
    local char = player.Character
    local foundFF = char:FindFirstChild("ForceField")
    if foundFF then
        button.Text = "PVP Mode"
        bg.Style = Enum.FrameStyle.ChatRed
    else
        button.Text = "Safe Mode"
        bg.Style = Enum.FrameStyle.ChatGreen
    end
    event:FireServer()
end

button.MouseButton1Click:Connect(forcefieldEvent)

I have tried adding another parameter that points to the Local Player, but that didn't work. Please help, thank you to whoever responds.