diff --git a/Distance.LevelMods/CustomObjectManager.cs b/Distance.LevelMods/CustomObjectManager.cs
index d9422ff..5f21b39 100644
--- a/Distance.LevelMods/CustomObjectManager.cs
+++ b/Distance.LevelMods/CustomObjectManager.cs
@@ -72,7 +72,11 @@ public static void Register(SerialComponent entryComp, byte[] data) {
             BinaryDeserializer.idToSerializableTypeMap_[entryComp.ID_] = entryComp.GetType();
 
             var root = man.LevelPrefabFileInfosRoot_;
-            root.AddChildInfo(new LevelPrefabFileInfo(entryComp.name, entryComp.gameObject, root));
+            var info = new LevelPrefabFileInfo(entryComp.name, entryComp.gameObject, root);
+            if (root.childInfos_.RemoveAll(info1 => info1.Name_ == info.Name_) > 0)
+                G.Sys.LevelEditor_.DoFramesLater(2, () => G.Sys.LevelEditor_.SetToolText(
+                    $"Updated prefab for custom object {entryComp.name}"));
+            root.AddChildInfo(info);
         }
     }
 }
diff --git a/Distance.LevelMods/Entry.cs b/Distance.LevelMods/Entry.cs
index 977f896..7a23057 100644
--- a/Distance.LevelMods/Entry.cs
+++ b/Distance.LevelMods/Entry.cs
@@ -17,9 +17,11 @@ public void Initialize(IManager manager) {
                 G.Sys.LevelEditor_.AddEventToRegisteredHotKeys(InputEvent.Create("ctrl+shift+o"),
                     LoadCustomObjectTool.info.Name_));
 
-            PostLoad.Subscribe(data =>
+            PostLoad.Subscribe(data => {
                 // remove custom object manager when a level loads
-                data.level_.TryDeleteLayer(data.level_.GetLayer(nameof(CustomObjectManager)), true));
+                var layer = data.level_.GetLayer(nameof(CustomObjectManager));
+                if (layer != null) data.level_.TryDeleteLayer(layer, true);
+            });
 
             RuntimePatcher.AutoPatch();
         }
diff --git a/Distance.LevelMods/Harmony.cs b/Distance.LevelMods/Harmony.cs
index 0fe7ddd..eef56a2 100644
--- a/Distance.LevelMods/Harmony.cs
+++ b/Distance.LevelMods/Harmony.cs
@@ -39,6 +39,8 @@ namespace Level_ {
         internal static class SaveToPath {
             [UsedImplicitly]
             private static void Prefix(Level __instance) {
+                if (__instance.FindComponentsOfType<CustomObject>().IsNullOrEmpty()) return;
+
                 var le = G.Sys.levelEditor_!;
 
                 var prefab = G.Sys.ResourceManager_.levelPrefabs_[nameof(CustomObjectManager)];