Program: 86069
Project: 86069
Buggy source:
public void openGUI(final String p){
  IconMenu iconm;
  int mincount=pli.getAClasses().keySet().size();
  if (lasticonm.containsKey(p)) {
    iconm=lasticonm.get(p);
  }
 else {
    iconm=new IconMenu(pli.getMessagesConfig().classes_item,(9 * plugin.getConfig().getInt("String_Node_Str") > mincount - 1) ? 9 * plugin.getConfig().getInt("String_Node_Str") : Math.round(mincount / 9) * 9 + 9,new IconMenu.OptionClickEventHandler(){
      @Override public void onOptionClick(      IconMenu.OptionClickEvent event){
        if (event.getPlayer().getName().equalsIgnoreCase(p)) {
          if (pli.global_players.containsKey(p)) {
            if (pli.getArenas().contains(pli.global_players.get(p))) {
              String d=event.getName();
              Player p=event.getPlayer();
            }
          }
        }
        event.setWillClose(true);
      }
    }
,plugin);
  }
  int c=0;
  for (  String ac : shopitems.keySet()) {
    ShopItem ac_=shopitems.get(ac);
    if (ac_.isEnabled()) {
      int slot=c;
      if (pli.getShopConfig().getConfig().isSet("String_Node_Str" + ac_.getInternalName() + "String_Node_Str")) {
        slot=pli.getShopConfig().getConfig().getInt("String_Node_Str" + ac_.getInternalName() + "String_Node_Str");
        if (slot < 0 || slot > iconm.getSize() - 1) {
          slot=c;
        }
      }
      iconm.setOption(slot,ac_.getIcon().clone(),ac_.getName(),pli.getShopConfig().getConfig().getString("String_Node_Str" + ac_.getInternalName() + "String_Node_Str").split("String_Node_Str"));
      c++;
    }
  }
  iconm.open(Bukkit.getPlayerExact(p));
  lasticonm.put(p,iconm);
}

Fixed version (ground truth):
public void openGUI(final String p){
  IconMenu iconm;
  int mincount=pli.getAClasses().keySet().size();
  if (lasticonm.containsKey(p)) {
    iconm=lasticonm.get(p);
  }
 else {
    iconm=new IconMenu(pli.getMessagesConfig().shop_item,(9 * plugin.getConfig().getInt("String_Node_Str") > mincount - 1) ? 9 * plugin.getConfig().getInt("String_Node_Str") : Math.round(mincount / 9) * 9 + 9,new IconMenu.OptionClickEventHandler(){
      @Override public void onOptionClick(      IconMenu.OptionClickEvent event){
        if (event.getPlayer().getName().equalsIgnoreCase(p)) {
          if (pli.global_players.containsKey(p)) {
            if (pli.getArenas().contains(pli.global_players.get(p))) {
              String d=event.getName();
              Player p=event.getPlayer();
            }
          }
        }
        event.setWillClose(true);
      }
    }
,plugin);
  }
  int c=0;
  for (  String ac : shopitems.keySet()) {
    ShopItem ac_=shopitems.get(ac);
    if (ac_.isEnabled()) {
      int slot=c;
      if (pli.getShopConfig().getConfig().isSet("String_Node_Str" + ac_.getInternalName() + "String_Node_Str")) {
        slot=pli.getShopConfig().getConfig().getInt("String_Node_Str" + ac_.getInternalName() + "String_Node_Str");
        if (slot < 0 || slot > iconm.getSize() - 1) {
          slot=c;
        }
      }
      iconm.setOption(slot,ac_.getIcon().clone(),ac_.getName(),pli.getShopConfig().getConfig().getString("String_Node_Str" + ac_.getInternalName() + "String_Node_Str").split("String_Node_Str"));
      c++;
    }
  }
  iconm.open(Bukkit.getPlayerExact(p));
  lasticonm.put(p,iconm);
}