[Benjo]

Even though I'm 99% sure, I just test-compiled it under OnPlayerRequestSpawn callback and it worked fine. Check that you haven't got too many/too little brackets { }.

pawn Код:

public OnPlayerRequestSpawn(playerid)
{
    if(IsLogged[playerid] == 1)
    {
        return 1;
    }
    else
    {
        SendClientMessage(playerid, COLOR_YELLOW, "ERROR: You can't spawn,maybe you arent registered or logged in.Use /register or /login");
        return 0;
    }
}