Program: 25216
Project: 25216
Buggy source:
public void onPlayerItem(PlayerItemEvent event){
  Block block=event.getBlockClicked();
  Player player=event.getPlayer();
  ItemStack is=player.getItemInHand();
  if (block != null && block.getTypeId() == 42) {
    short durability=is.getDurability();
    if (mcm.getInstance().isArmor(is) && block.getTypeId() == 42) {
      if (mcm.getInstance().isDiamondArmor(is) && mcm.getInstance().hasDiamond(player)) {
        mcm.getInstance().removeDiamond(player);
        player.getItemInHand().setDurability(mcm.getInstance().getArmorRepairAmount(is,player));
        mcUsers.getProfile(player).skillUpRepair(1);
        player.sendMessage(ChatColor.YELLOW + "String_Node_Str" + mcUsers.getProfile(player).getRepair()+ "String_Node_Str");
      }
 else       if (mcm.getInstance().isIronArmor(is) && mcm.getInstance().hasIron(player)) {
        player.sendMessage(ChatColor.DARK_RED + "String_Node_Str");
        player.sendMessage(ChatColor.YELLOW + "String_Node_Str");
      }
    }
    if (mcm.getInstance().isTools(is) && block.getTypeId() == 42) {
      if (mcm.getInstance().isIronTools(is) && mcm.getInstance().hasIron(player)) {
        is.setDurability(mcm.getInstance().getToolRepairAmount(is,durability,player));
        mcm.getInstance().removeIron(player);
        mcUsers.getProfile(player).skillUpRepair(1);
        player.sendMessage(ChatColor.YELLOW + "String_Node_Str" + mcUsers.getProfile(player).getRepair()+ "String_Node_Str");
      }
 else       if (mcm.getInstance().isDiamondTools(is) && mcm.getInstance().hasDiamond(player) && mcUsers.getProfile(player).getRepairInt() > 50) {
        is.setDurability(mcm.getInstance().getToolRepairAmount(is,durability,player));
        mcm.getInstance().removeDiamond(player);
        mcUsers.getProfile(player).skillUpRepair(1);
        player.sendMessage(ChatColor.YELLOW + "String_Node_Str" + mcUsers.getProfile(player).getRepair()+ "String_Node_Str");
      }
 else       if (mcm.getInstance().isDiamondTools(is) && mcUsers.getProfile(player).getRepairInt() < 50) {
        player.sendMessage(ChatColor.DARK_RED + "String_Node_Str");
      }
 else       if (mcm.getInstance().isDiamondTools(is) && !mcm.getInstance().hasDiamond(player) || mcm.getInstance().isIronTools(is) && !mcm.getInstance().hasIron(player)) {
        if (!mcm.getInstance().hasDiamond(player))         player.sendMessage(ChatColor.DARK_RED + "String_Node_Str" + ChatColor.BLUE+ "String_Node_Str");
        if (!mcm.getInstance().hasIron(player))         player.sendMessage(ChatColor.DARK_RED + "String_Node_Str" + ChatColor.GRAY+ "String_Node_Str");
      }
 else       if (mcm.getInstance().isDiamondArmor(is) && !mcm.getInstance().hasDiamond(player)) {
        player.sendMessage(ChatColor.DARK_RED + "String_Node_Str" + ChatColor.BLUE+ "String_Node_Str");
      }
 else       if (mcm.getInstance().isIronArmor(is) && !mcm.getInstance().hasIron(player))       player.sendMessage(ChatColor.DARK_RED + "String_Node_Str" + ChatColor.GRAY+ "String_Node_Str");
    }
  }
}

Fixed version (ground truth):
public void onPlayerItem(PlayerItemEvent event){
  Block block=event.getBlockClicked();
  Player player=event.getPlayer();
  ItemStack is=player.getItemInHand();
  if (block != null && block.getTypeId() == 42) {
    short durability=is.getDurability();
    if (mcm.getInstance().isArmor(is) && block.getTypeId() == 42) {
      if (mcm.getInstance().isDiamondArmor(is) && mcm.getInstance().hasDiamond(player)) {
        mcm.getInstance().removeDiamond(player);
        player.getItemInHand().setDurability(mcm.getInstance().getArmorRepairAmount(is,player));
        mcUsers.getProfile(player).skillUpRepair(1);
        player.sendMessage(ChatColor.YELLOW + "String_Node_Str" + mcUsers.getProfile(player).getRepair()+ "String_Node_Str");
      }
 else       if (mcm.getInstance().isIronArmor(is) && mcm.getInstance().hasIron(player)) {
        player.sendMessage(ChatColor.DARK_RED + "String_Node_Str");
        player.sendMessage(ChatColor.YELLOW + "String_Node_Str");
      }
    }
    if (mcm.getInstance().isTools(is) && block.getTypeId() == 42) {
      if (mcm.getInstance().isIronTools(is) && mcm.getInstance().hasIron(player)) {
        is.setDurability(mcm.getInstance().getToolRepairAmount(is,durability,player));
        mcm.getInstance().removeIron(player);
        mcUsers.getProfile(player).skillUpRepair(1);
        player.sendMessage(ChatColor.YELLOW + "String_Node_Str" + mcUsers.getProfile(player).getRepair()+ "String_Node_Str");
      }
 else       if (mcm.getInstance().isDiamondTools(is) && mcm.getInstance().hasDiamond(player) && mcUsers.getProfile(player).getRepairInt() > 50) {
        is.setDurability(mcm.getInstance().getToolRepairAmount(is,durability,player));
        mcm.getInstance().removeDiamond(player);
        mcUsers.getProfile(player).skillUpRepair(1);
        player.sendMessage(ChatColor.YELLOW + "String_Node_Str" + mcUsers.getProfile(player).getRepair()+ "String_Node_Str");
      }
 else       if (mcm.getInstance().isDiamondTools(is) && mcUsers.getProfile(player).getRepairInt() < 50) {
        player.sendMessage(ChatColor.DARK_RED + "String_Node_Str");
      }
 else       if (mcm.getInstance().isDiamondTools(is) && !mcm.getInstance().hasDiamond(player) || mcm.getInstance().isIronTools(is) && !mcm.getInstance().hasIron(player)) {
        if (mcm.getInstance().isDiamondTools(is) && !mcm.getInstance().hasDiamond(player))         player.sendMessage(ChatColor.DARK_RED + "String_Node_Str" + ChatColor.BLUE+ "String_Node_Str");
        if (mcm.getInstance().isIronTools(is) && !mcm.getInstance().hasIron(player))         player.sendMessage(ChatColor.DARK_RED + "String_Node_Str" + ChatColor.GRAY+ "String_Node_Str");
      }
 else       if (mcm.getInstance().isDiamondArmor(is) && !mcm.getInstance().hasDiamond(player)) {
        player.sendMessage(ChatColor.DARK_RED + "String_Node_Str" + ChatColor.BLUE+ "String_Node_Str");
      }
 else       if (mcm.getInstance().isIronArmor(is) && !mcm.getInstance().hasIron(player))       player.sendMessage(ChatColor.DARK_RED + "String_Node_Str" + ChatColor.GRAY+ "String_Node_Str");
    }
  }
}