How to reproduce:
1. Create a new Universal 3D Sample Project
2. Open Package Manager window (Window -> Package Manager)
3. Click the "+" icon
4. Click "Install package from git URL"
5. Type "com.unity.entities@1.3.0-pre.4" and press enter
6. Create a New Sub Scene (Right-click in the Hierarchy window > New Sub Scene > Empty Scene…)
7. Enter the Play Mode in the Editor
8. Disable and Enable “New Sub Scene”
9. Exit the Play Mode in the Editor
10. Observe the Console window

Expected result: No errors are thrown in the Console window
Actual result: “ArgumentException” error is spammed in the Console window

Reproducible with: 1.3.0-pre.4 (6000.0.13f1)

Reproduced on: macOS Sonoma 14.5

Error:

{code:java}
ArgumentException: An item with the same key has already been added. Key: df1f9bad8f3b3455f9d221b5b4157258
System.Collections.Generic.Dictionary`2[TKey,TValue].TryInsert (TKey key, TValue value, System.Collections.Generic.InsertionBehavior behavior) (at <ce95f63947c64e4bbf5929ebe610c440>:0)
System.Collections.Generic.Dictionary`2[TKey,TValue].Add (TKey key, TValue value) (at <ce95f63947c64e4bbf5929ebe610c440>:0)
Unity.Scenes.Editor.LiveConversionConnection.Update (System.Collections.Generic.List`1[T] changeSets, Unity.Collections.NativeList`1[T] loadScenes, Unity.Collections.NativeList`1[T] unloadScenes, Unity.Scenes.LiveConversionMode mode) (at ./Library/PackageCache/com.unity.entities/Unity.Scenes.Editor/LiveConversion/LiveConversionConnection.cs:323)
Unity.Scenes.Editor.EditorSubSceneLiveConversionSystem.OnUpdate () (at ./Library/PackageCache/com.unity.entities/Unity.Scenes.Editor/EditorSubSceneLiveConversionSystem.cs:62)
Unity.Entities.SystemBase.Update () (at ./Library/PackageCache/com.unity.entities/Unity.Entities/SystemBase.cs:418)
Unity.Entities.ComponentSystemGroup.UpdateAllSystems () (at ./Library/PackageCache/com.unity.entities/Unity.Entities/ComponentSystemGroup.cs:723)
UnityEngine.Debug:LogException(Exception)
Unity.Debug:LogException(Exception) (at ./Library/PackageCache/com.unity.entities/Unity.Entities/Stubs/Unity/Debug.cs:17)
Unity.Entities.ComponentSystemGroup:UpdateAllSystems() (at ./Library/PackageCache/com.unity.entities/Unity.Entities/ComponentSystemGroup.cs:728)
Unity.Entities.ComponentSystemGroup:OnUpdate() (at ./Library/PackageCache/com.unity.entities/Unity.Entities/ComponentSystemGroup.cs:681)
Unity.Scenes.Editor.LiveConversionEditorSystemGroup:OnUpdate() (at ./Library/PackageCache/com.unity.entities/Unity.Scenes.Editor/LiveConversion/LiveConversionEditorSystemGroup.cs:15)
Unity.Entities.SystemBase:Update() (at ./Library/PackageCache/com.unity.entities/Unity.Entities/SystemBase.cs:418)
Unity.Entities.ComponentSystemGroup:UpdateAllSystems() (at ./Library/PackageCache/com.unity.entities/Unity.Entities/ComponentSystemGroup.cs:723)
Unity.Entities.ComponentSystemGroup:OnUpdate() (at ./Library/PackageCache/com.unity.entities/Unity.Entities/ComponentSystemGroup.cs:681)
Unity.Entities.InitializationSystemGroup:OnUpdate() (at ./Library/PackageCache/com.unity.entities/Unity.Entities/DefaultWorld.cs:169)
Unity.Entities.SystemBase:Update() (at ./Library/PackageCache/com.unity.entities/Unity.Entities/SystemBase.cs:418)
Unity.Entities.DummyDelegateWrapper:TriggerUpdate() (at ./Library/PackageCache/com.unity.entities/Unity.Entities/ScriptBehaviourUpdateOrder.cs:523)
{code}