diff --git a/Pal.Client/Configuration.cs b/Pal.Client/Configuration.cs
index 03f982f..0e60483 100644
--- a/Pal.Client/Configuration.cs
+++ b/Pal.Client/Configuration.cs
@@ -1,9 +1,12 @@
 using Dalamud.Configuration;
 using Dalamud.Logging;
+using ECommons.Schedulers;
 using Newtonsoft.Json;
 using Pal.Client.Scheduled;
 using System;
+using System.Collections.Concurrent;
 using System.Collections.Generic;
+using System.IO;
 using System.Linq;
 using System.Numerics;
 using System.Security.Cryptography;
@@ -84,6 +87,48 @@ namespace Pal.Client
                 Version = 4;
                 Save();
             }
+
+            if (Version == 4)
+            {
+                // 2.2 had a bug that would mark chests as traps, there's no easy way to detect this -- or clean this up.
+                // Not a problem for online players, but offline players might be fucked.
+                bool changedAnyFile = false;
+                LocalState.ForEach(s =>
+                {
+                    foreach (var marker in s.Markers)
+                        marker.SinceVersion = "0.0";
+
+                    var lastModified = File.GetLastWriteTimeUtc(s.GetSaveLocation());
+                    if (lastModified >= new DateTime(2023, 2, 3, 0, 0, 0, DateTimeKind.Utc))
+                    {
+                        s.Backup(suffix: "bak");
+
+                        s.Markers = new ConcurrentBag<Marker>(s.Markers.Where(m => m.SinceVersion != "0.0" || m.Type == Marker.EType.Hoard || m.WasImported));
+                        s.Save();
+
+                        changedAnyFile = true;
+                    }
+                    else
+                    {
+                        // just add version information, nothing else
+                        s.Save();
+                    }
+                });
+
+                // Only notify offline users - we can just re-download the backup markers from the server seamlessly.
+                if (Mode == EMode.Offline && changedAnyFile)
+                {
+                    new TickScheduler(delegate
+                    {
+                        Service.Chat.PrintError("[Palace Pal] Due to a bug, some coffers were accidentally saved as traps. To fix the related display issue, locally cached data was cleaned up.");
+                        Service.Chat.PrintError($"If you have any backup tools installed, please restore the contents of '{Service.PluginInterface.GetPluginConfigDirectory()}' to any backup from February 2, 2023 or before.");
+                        Service.Chat.PrintError("You can also manually restore .json.bak files (by removing the '.bak') if you have not been in any deep dungeon since February 2, 2023.");
+                    }, 2500);
+                }
+
+                Version = 5;
+                Save();
+            }
         }
 #pragma warning restore CS0612 // Type or member is obsolete
 
diff --git a/Pal.Client/LocalState.cs b/Pal.Client/LocalState.cs
index 8929b12..d2bff21 100644
--- a/Pal.Client/LocalState.cs
+++ b/Pal.Client/LocalState.cs
@@ -80,6 +80,26 @@ namespace Pal.Client
             string path = GetSaveLocation(TerritoryType);
 
             ApplyFilters();
+            SaveImpl(path);
+        }
+
+        public void Backup(string suffix)
+        {
+            string path = $"{GetSaveLocation(TerritoryType)}.{suffix}";
+            if (!File.Exists(path))
+            {
+                SaveImpl(path);
+            }
+        }
+
+        private void SaveImpl(string path)
+        {
+            foreach (var marker in Markers)
+            {
+                if (string.IsNullOrEmpty(marker.SinceVersion))
+                    marker.SinceVersion = typeof(Plugin).Assembly.GetName().Version!.ToString(2);
+            }
+
             if (Markers.Count == 0)
                 File.Delete(path);
             else
@@ -92,18 +112,25 @@ namespace Pal.Client
             }
         }
 
+        public string GetSaveLocation() => GetSaveLocation(TerritoryType);
+
         private static string GetSaveLocation(uint territoryType) => Path.Join(Service.PluginInterface.GetPluginConfigDirectory(), $"{territoryType}.json");
 
-        public static void UpdateAll()
+        public static void ForEach(Action<LocalState> action)
         {
             foreach (ETerritoryType territory in typeof(ETerritoryType).GetEnumValues())
             {
                 LocalState? localState = Load((ushort)territory);
                 if (localState != null)
-                    localState.Save();
+                    action(localState);
             }
         }
 
+        public static void UpdateAll()
+        {
+            ForEach(s => s.Save());
+        }
+
         public void UndoImport(List<Guid> importIds)
         {
             // When saving a floor state, any markers not seen, not remote seen, and not having an import id are removed;
diff --git a/Pal.Client/Marker.cs b/Pal.Client/Marker.cs
index 12bb253..41f5b8f 100644
--- a/Pal.Client/Marker.cs
+++ b/Pal.Client/Marker.cs
@@ -50,6 +50,11 @@ namespace Pal.Client
 
         public bool WasImported { get; set; }
 
+        /// <summary>
+        /// To make rollbacks of local data easier, keep track of the version which was used to write the marker initially.
+        /// </summary>
+        public string SinceVersion { get; set; }
+
         [JsonIgnore]
         public Element? SplatoonElement { get; set; }