Return 0 for null table entry.

src/engine/gameManager/ForgeManager.java

@@ -393,6 +393,12 @@ public enum ForgeManager implements Runnable {
         if (rollForModifier < 80) {
             int randomModifier = LootManager.TableRoll(vendor.getLevel(), false);
             modTableEntry = ModTableEntry.rollTable(modTypeTableEntry.modTableID, randomModifier);
+
+            // @TODO : Figure out how a null can be returned from a defined set.
+
+            if (modTableEntry == null)
+                return 0;
+
             EffectsBase effectsBase = PowersManager.getEffectByIDString(modTableEntry.action);
             modifier = effectsBase.getToken();
         }