Initialize all collections for npc

src/engine/objects/NPC.java

@@ -869,10 +869,12 @@ public class NPC extends AbstractCharacter {
         if (this.building != null)
             NPCManager.slotCharacterInBuilding(this);
 
-        // If NPC is a vendor create arraylist for forge
+        // If NPC is a vendor then configure ForgeManager support
 
-        if (this.contract.isTrainer() == false)
+        if (this.contract.isTrainer() == false) {
             ForgeManager.vendorItemLookup.computeIfAbsent(this, k -> new ArrayList<>()); // Forge lookup
+            ForgeManager.vendorWorkOrderLookup.computeIfAbsent(this, k -> new ArrayList<>());
+        }
 
         this.symbol = this.contract.getIconID();
         this.modTypeTable = this.contract.getNPCModTypeTable();