So I am making a Roblox game and everything went well, i fixed all the issues except this one, I can’t figure out why it doesn’t work and still says "attempt to compare number < Instance" because I need a remote event from the client’s side to fix the capacity of the backpack (I need to put the default value at 10 but it is 0 because it is just for rising events and being sure that it doesn’t cause more code in the same script and be lost).

I checked the client’s side if I used a number value or just number: only 10 – I checked the parameters of the remote event on the server’s side script: number – I checked if I used a variable at the beginning of the script, I changed the parameter’s name: still error… I checked Roblox’s devforum, nothing (don’t ask me why I don’t use devforum)

Code:

Server sided script

remoteEvents:FindFirstChild("FixBackpackCapacity").OnServerEvent:Connect(function(player, maxCapacityFC : number)

   if maxCapacityFC ~= nil and maxCapacityFC > 0 then
      player:FindFirstChild(player.EquippedBackpack.Value):FindFirstChild("MaxCapacity").Value = maxCapacityFC
    
   end

end)

Client sided script

game:GetService("ReplicatedStorage").RemoteEvents.FixBackpackCapacity:FireServer(player, 10)

Notes

1. I tried to remove maxCapacityFC ~= nil, it is still triggering the same error
2. It is at the right place, the condition is the problem

>Solution :

When you fire a RemoteEvent from the client, the player object is supplied by the engine to the server. For example, if the client passes a, b, c, the server will receive player, a, b, c.

In your case, the client is providing player, 10, so the server is receiving player, player, 10. That is why maxCapacityFC is acting like an Instance, because it has been assigned as an Instance of a Player.

To fix your issue, simply remove the player variable from the FireServer call.

local ReplicatedStorage = game:GetService("ReplicatedStorage")
local FixBackpackCapacity = ReplicatedStorage.RemoteEvents.FixBackpackCapacity

FixBackpackCapacity:FireServer(10)