Why am I getting this error?

[lexishh]

I am making a boombox system and need to fire some events however I am getting this error

Server code:

Client Code:

[WaterJamesPlough (Neil)]

in Client code you don’t need the Player Instance in FireServer, you just need to pass in the input arguements you want on server side, the player is automatically passed Internally

[lexishh]

Thanks! This is probably the quickest soloution I’ve ever given out

[Syclya (zzz)]

To sum it up:
soundid in this case is the player instance you sent from the client.
As player is automatically passed, it would look like this in your example:

.OnServerEvent:Connect(function(Player1, Player2, Argument) end)