Whats wrong with this? Please help!

@EventHandler
public void onBlockBreak(BlockBreakEvent event) {

Sign sign = (Sign) event.getBlock().getState();
String arenaName = sign.getLine(2);

World w = Bukkit.getWorld(plugin.getConfig().getString("LobbySign." + arenaName + ".World"));
int x = plugin.getConfig().getInt("LobbySign." + arenaName + ".x");
int y = plugin.getConfig().getInt("LobbySign." + arenaName + ".y");
int z = plugin.getConfig().getInt("LobbySign." + arenaName + ".z");
if(event.getBlock().getWorld() == w || event.getBlock().getLocation().getBlockX() == x || event.getBlock().getLocation().getBlockY() == y || event.getBlock().getLocation().getBlockZ() == z){
if(event.getBlock().getType() == Material.WALL_SIGN || event.getBlock().getType() == Material.SIGN_POST){
plugin.getConfig().set("LobbySign." + arenaName, null);
plugin.saveConfig();
}
}

}

Never mind i got it. I just needed to check the material before i casted sign.

EDIT by Moderator: merged posts, please use the edit button instead of double posting.