fixed bug

src/net/citizensnpcs/npc/CitizensNPC.java

@@ -100,7 +100,7 @@ public abstract class CitizensNPC extends AbstractNPC {
 
     @Override
     public boolean openInventory(Player player) {
-        if (!isSpawned() || getTrait(Inventory.class).getContents() == null)
+        if (!isSpawned())
             return false;
         getInventory().setContents(getTrait(Inventory.class).getContents());
         inventory.show(player);

src/net/citizensnpcs/trait/Inventory.java

@@ -17,6 +17,7 @@ public class Inventory implements Trait {
     private ItemStack[] contents;
 
     public Inventory() {
+        contents = new ItemStack[36];
     }
 
     public Inventory(org.bukkit.inventory.Inventory inventory) {