My face changer gui isnt working?

Hello!

So, the method you are using to change the player's face won't work. I re-wrote your script using HumanoidDescription and it works completely fine.

Here is the code:

ServerScript

local ReplicatedStorage = game:GetService("ReplicatedStorage")
local remoteFaceTest_1 = ReplicatedStorage:WaitForChild('RemoteFaceTest1')

remoteFaceTest_1.OnServerEvent:Connect(function(player, facechange) 
	local humanoid = player.Character and player.Character:FindFirstChild("Humanoid")
	if humanoid then
		local descriptionClone = humanoid:GetAppliedDescription()
		descriptionClone.Face = facechange
		humanoid:ApplyDescription(descriptionClone)
	end
end)

LocalScript

local ReplicatedStorage = game:GetService("ReplicatedStorage")
local remoteFaceTest1 = ReplicatedStorage:WaitForChild('RemoteFaceTest1')

script.Parent.MouseButton1Click:Connect(function() 
	remoteFaceTest1:FireServer(12145366) 
end)

I hope it works for you! If you need any questions, feel free to reply to this answer.

Sincerely, Ziruken