Unable to cast instance to int64

[Berrinlin (Rephy)]

Hello, I am trying to make an outfit loader where players can type in someone else’s user name and load in their outfit. For some reason though, I get this error, “Unable to cast instance to int64” in the 4th line of my script (server). I cannot think of any solutions, why might this be happening?

Local script:

local plr = game.Players.LocalPlayer
local button = script.Parent
local input = button.Parent.Input
local event = game.ReplicatedStorage.LoadPlayerOutfit

button.MouseButton1Click:Connect(function()
	local success, errormessage = pcall(function()
		return game.Players:GetUserIdFromNameAsync(input.Text)
	end)
	if success then
		event:FireServer(plr, game.Players:GetUserIdFromNameAsync(input.Text))
	else
		warn(errormessage)
	end
end)

Script:

local event = game.ReplicatedStorage.LoadPlayerOutfit

event.OnServerEvent:Connect(function(plr, ID)
	local desc = game.Players:GetHumanoidDescriptionFromUserId(game.Players:GetHumanoidDescriptionFromUserId(ID))
	plr.Character.Humanoid:ApplyDescription(desc)
end)

Thanks for reading!

[p49p0 (Citrullus)]

@Berrinlin

local desc = game.Players:GetHumanoidDescriptionFromUserId(game.Players:GetHumanoidDescriptionFromUserId(ID))

you used the same function twice.

[DasKairo (Cairo)]

@Berrinlin

game.Players:GetHumanoidDescriptionFromUserId(game.Players:GetHumanoidDescriptionFromUserId(ID))

This would be your Issue.

What GetHumanoidDescriptionFromUserId does is return a HumanoiDescription based on the UserId given, what the error means by int64 is a 64 bit signed integer, which is a whole number that has a limit of 2^63 - 1, what the function is getting is the exact same function that is either returning nil, or a HumanoidDescription, which arent numbers, the function sees that they arent numbers, and gives the error: Unable to cast instance to int64, which if you notice Instance, that means it returned a HumanoidDescription, so you need to remove one of the functions.

[Berrinlin (Rephy)]

I figured out the problem myself, although yes, GetHumanoidDescription() returns an Instance. I decided to test something out. In my local script, I replaced the first fireserver() parameter with “Hi” and had my script print that parameter out. I got “Berrinlin” printed instead, which is my username. Apparently, OnServerEvent functions take an extra parameter which is the player who’s local script called the server event.