fixed loot generation array size bug

src/engine/loot/ItemTableEntry.java

@@ -51,7 +51,7 @@ public class ItemTableEntry {
 
         itemTableEntryList = LootManager._itemTables.get(itemTable);
 
-        if(itemTableEntryList != null){
+        if(itemTableEntryList != null && itemTableEntryList.size() > 0){
             id =  itemTableEntryList.get(ThreadLocalRandom.current().nextInt(0,itemTableEntryList.size() - 1)).cacheID;
         }
         return id;