Tried to use a NULL entity!

[Spicywin]

function PlayerSay(ply, txt, pub)
    if txt != "!adminskin" then return end

    model = ""
    if ply:AccountID() == 861040666 then
        model = "models/player/ianmata1998/whealteyii.mdl"
    end

    if IsValid(ply) then
        net.Start("ply_say")
            net.WriteEntity(ply)
            net.WriteString(model)
        net.Send()
    end
end
hook.Add("PlayerSay", "ply_say", PlayerSay)

Though IsValid(ply) returns true all time. I'm getting the error on net.Send()
Screenshot of the error:

https://files.facepunch.com/forum/upload/246845/5e06f159-9dff-4ee5-85e8-788906239db0/Screenshot_2.png

(sv_commands.lua:25 -> net.Send())

[mcNuggets]

You check for IsValid when you already checked for AccountID.
You have to do it before.

[Spicywin]

Ooops, how ridiculous.
That helped, thank you.