From 790cb5d7332f2b0dad0e190efa2bc3424430a0e8 Mon Sep 17 00:00:00 2001
From: Tellundro <101518037+tellundro@users.noreply.github.com>
Date: Wed, 4 May 2022 23:10:55 -0300
Subject: [PATCH] fix: Fixes NPE in TreasureMapChest (#1010)

---
 Projects/UOContent/Items/Containers/TreasureMapChest.cs | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/Projects/UOContent/Items/Containers/TreasureMapChest.cs b/Projects/UOContent/Items/Containers/TreasureMapChest.cs
index 03e7922ee..5b3153892 100644
--- a/Projects/UOContent/Items/Containers/TreasureMapChest.cs
+++ b/Projects/UOContent/Items/Containers/TreasureMapChest.cs
@@ -361,12 +361,12 @@ public partial class TreasureMapChest : LockableContainer
 
     public override void OnItemLifted(Mobile from, Item item)
     {
-        var notYetLifted = !_lifted.Contains(item);
-
+        var notYetLifted = _lifted?.Contains(item) != true; 
         from.RevealingAction();
 
         if (notYetLifted)
         {
+            _lifted ??= new HashSet<Item>();
             _lifted.Add(item);
 
             if (Utility.RandomDouble() <= 0.1) // 10% chance to spawn a new monster