Cannot add item to inventory (Bukkit/Spigot)

Question

I have some problems with my kits plugin for Bukkit and Spigot. When I use the command /kits only an empty inventory opens. Here's my code:

        for (int i = 0; i<main.cfg.getConfigurationSection("kits").getKeys(false).size();i++) {
            String s = (String) main.cfg.getConfigurationSection("kits").getKeys(false).toArray()[i];
            ItemStack is = new ItemStack(Material.valueOf(main.cfg.getString("kits." + s + ".mat")));
            ItemMeta im = is.getItemMeta();
            im.setDisplayName(s);
            is.setItemMeta(im);
            cont.add(is);
        }

the item stack is valid, but when I do kits.add (is) the item doesn't get added to the inventory.

• I have created the inventory kits with Bukkit.createInventory(null,size,"Kits"); and it shows up correctly
• After I have added all items, I open up the inventory with ((Player)sender).openInventory(kits);

You see cont.add(is) in the code, because I've tried to make a list of ItemStack (cont) and then in another for loop add all items to the inventory, but that shouldn't make a difference.

Answer 1

I found a solution for this problem. It was because I calculated the size of the inventory depending on how many kits there are. Today I wondered why I had 3 lines in the inventory and just 1 kit. that should only make 1 line. then I set it to 54 items so 6 lines as inventory size and it worked! Solution: make sure that you're creating at least 3 lines in your inventory, then it should work.