Performance warning: There are more than 100 preview scenes.

Version: 2021.1.0f1

I keep getting this warning message in the console, "[Worker0] Performance warning: There are more than 100 preview scenes. There might be code not releasing the preview scene after creating it." Does anyone know where to start looking to resolve this? I comes along with another warning, "[Worker0] Unable to allocate new scene culling mask".

Clearing it's telling me something is not getting deallocated when running/stopping playing in the editor. I just have no idea how to hunt this down.

 

me too, and this happened when I updated my Engine to 2021.1
the full message i get is like this:
[Worker1] Performance warning. There are more than 100 preview scenes. There might be code not releasing the preview scene after creating it.

 

@jonathans42 of course it's gone away now but I'll be sure to upload the log here if it happens again.

 

Ran into this bug in my current project, attaching logs here.

 

how to resolved it if 3rdparyt libray cause it？

 

Same issue here, causing all asset previews to disappear. Pretty annoying to navigate in the project windows without them.
I have many 3rd party libs, Odin, ProBuilder, Dotween .. Hard to tell, I've used them for a long time in every projects

 

The two warnings pop out after creating a prefab from the hierarchy for instance (or if I duplicate a material, but not only)

• [Worker0] Unable to allocate new scene culling mask
• [Worker0] Performance warning: There are more than 100 preview scenes. There might be code not releasing the preview scene after creating it.

I've captured the editor log :

Spoiler: Editor Log

Start importing Assets/_Project/Prefabs/Blocks/Tree Leave.prefab using Guid(fcb39a50b2806b2419d132528b3835cf) Importer(-1,00000000000000000000000000000000) -> (artifact id: '56e627b56eede2da0368b548f19fe612') in 0.066068 seconds
Refreshing native plugins compatible for Editor in 1.31 ms, found 3 plugins.
Preloading 0 native plugins for Editor in 0.00 ms.
RefreshInfo: StopAssetImportingV2(NoUpdateAssetOptions) scanfilter:
RefreshProfiler: Total: 425.578ms
InvokeBeforeRefreshCallbacks: 0.000ms
ApplyChangesToAssetFolders: 0.054ms
Scan: 7.421ms
OnSourceAssetsModified: 0.592ms
InitializeImportedAssetsSnapshot: 8.883ms
GetAllGuidsForCategorization: 1.199ms
CategorizeAssets: 7.543ms
ImportAndPostprocessOutOfDateAssets: 348.332ms (3.865ms without children)
ImportManagerImport: 69.605ms (3.112ms without children)
ImportInProcess: 66.464ms
UpdateCategorizedAssets: 0.029ms
PostProcessAllAssets: 262.450ms
ReloadImportedAssets: 0.000ms
EnsureUptoDateAssetsAreRegisteredWithGuidPM: 0.717ms
InitializingProgressBar: 0.003ms
PostProcessAllAssetNotificationsAddChangedAssets: 0.444ms
OnDemandSchedulerStart: 0.443ms
RestoreLoadedAssetsState: 3.952ms
UpdateImportedAssetsSnapshot: 6.854ms
ReloadSourceAssets: 1.694ms
UnloadImportedAssets: 0.217ms
Hotreload: 40.814ms
FixTempGuids: 0.005ms
GatherAllCurrentPrimaryArtifactRevisions: 0.276ms
UnloadStreamsBegin: 0.141ms
LoadedImportedAssetsSnapshotReleaseGCHandles: 1.888ms
GetLoadedSourceAssetsSnapshot: 7.872ms
PersistCurrentRevisions: 0.361ms
UnloadStreamsEnd: 0.129ms
GenerateScriptTypeHashes: 0.065ms
Untracked: -1.845ms
Start ondemand import (priority ImportantBackground): Assets/_Project/Prefabs/Blocks/Tree Leave.prefab (Guid(fcb39a50b2806b2419d132528b3835cf) Importer(815301076,1909f56bfc062723c751e8b465ee728b))
[Worker0] Start importing Assets/_Project/Prefabs/Blocks/Tree Leave.prefab using Guid(fcb39a50b2806b2419d132528b3835cf) Importer(815301076,1909f56bfc062723c751e8b465ee728b) [Worker0] Unable to allocate new scene culling mask

[Worker0] Performance warning: There are more than 100 preview scenes. There might be code not releasing the preview scene after creating it.

[Worker0] -> (artifact id: '584b6606d93855aae8b77c29b60d6f15') in 0.129636 seconds

Immediately after, all Project previews are cleared / disappear :/

 

Thanks for your reactivity!
I indeed suspect the warnings to be triggered by a third party plugin but they disappeared and I cannot reproduce the bug now

 

how do you attach the two files to stop the bug?

 

Same problem here. I'm using visual scripting and 2d packages just from unity registry, no third party packages. The error often happens when I'm duplicating prefabs. Or crating new ones form hierarchy. (simple prefabs just empty object as container with one child object (sprite). hmm

 

i am using mac but i can't seem to find a folder in finder with the unity/editor/etc. can you help me

 

It is probably a hidden folder. You can see it via the terminal if you type in "ls -la", but if you don't know how to navigate in terminals, then google says: "A quick and easy way to find secret files within a folder is to open the Finder and press Command + Shift + . (full stop/period)".

 

Same issue right when I started duplicated items in my prefab

 

I solved the problem just by caching the "Temporary" scene and resetting it when it needs to be used again by removing all objects except the camera and light. By pooling the scene this way, I'm not destroying and creating scenes and only ever use one. I haven't noticed any negative impacts on performance to generate thumbnail previews.

This isn't a solution imo because destroying or closing the scene should remove it completely so that if you create another then you're back up to the same number as was used before when you had created the first one, but it seems that destroying the scene doesn't actually destroy it like it's supposed to, it just invalidates it so that the methods that depend on an initialized scene don't work anymore.

Unless we're all doing something wrong in how we "destroy" it? But so far I've not seen anything in the documentation that indicates that.

 

unity 2021.2f still get this error...

 

Same warning here : 2021.2.0f1

 

@jonathans42

Still happens on 2021.2.0f1, here are the logs, 7zipped as they're pretty big otherwise.

Thanks for your help

 

@jonathans42

Here's a repro: https://fogbugz.unity3d.com/default.asp?1379580_e5stl277bafvl13k

10 folders, each with 10 assets, each with 10 GOs, materials, textures, that was enough to break the previews.

Hopefully you'll be able to spot and fix the issue!

Thanks

 

@jonathans42

Forgot to mention, in any case when you start the project the errors don't show up, right-click Assets and Reimport, then after that, select all the folders to see all the assets, the errors will pop up.

That brings another question, why aren't the previews being triggerred at startup ? Because when starting Unity, none of the previews are actually shown.

Thanks

 

This is puzzling to say the least, here, at some point after reimporting the folder, some will start appearing as you scroll down and then of course, others will not as the warnings are being shown in the console.

What's even more puzzling is that now I've upgraded to latest version, the bug is simply gone!!! It hasn't happened a single time and all the previews are always visible. (but there's nothing mentioning it in the release notes)

One thing's weird for sure is the asset index window, it always shows Loading the index... even though if you let the background task run to completion, save the project and restart Unity afterwards. (not sure if that has any influence though)

 

After thoroughly testing that stuff these last days, here are my findings:

I've upgraded to 2021.2.3f1,

The index will never update itself unless you double-click the asset to open it, this, even though if you, say, try to create a new material to trigger an index update.

However, I got the Loading the index... problem fixed somehow, this, by deleting the index asset itself and creating a new one; not sure if it got corrupted in some way as it was created on a previous version of Unity, still, the problem is gone and the index itself appears to be more reactive.

Last but not least, the warnings about the inability to create scene previews are gone and all the previews are working as expected. Something's definitely been fixed in Unity as the last two versions exhibited a bug in the project browser: the background of assets was mostly the same like project browser window background color; now it's back to a darker tone as usual.

And to reply to your question... In fact, the build button has apparently always worked... I just figured out that by moving the mouse into both the asset window and the background tasks window, they get refreshed once the mouse in and show what is expected; so it looks like a very simple repaint bug to fix!

 

encountering this on 2021.2.0f1 seems to occur anytime I create a texture asset and then save it to the asset database (overwriting the existing texture asset, such as a cubemap), eventually the preview window for the texture stops displaying and it spams the warning.

Also have the issue where assets that get saved over with
AssetDatabase.CreateAsset cannot be deleted or refreshed until an assembly reload, (displays the "The operation "SoftDelete" cannot be executed because the selection is a root folder." warning) which is a separate issue but related to saving over an existing asset.

 

Encountering this issue on 2021.1.24f1.

Also getting perhaps related issues that i can not tell how to replicate:
Sometimes I get a single editor error if i Hit play after loading project and i have something selected in the Hierarchy that moves.
Sometimes when i'm searching through project files, i get warning spam when i'm moving the mouse anywhere. Stops when i clear the search field with the "x".

I'll update this post or repost when/if i get exact error message/trace of these issues again. But basically there seem to be many editor related rendering issues that started since i upgraded to 2021s.

 

Try restarting Unity it worked for me

 

Did this ever get resolved as I am not seeing the solution here?

 

Now I also got the same problem on Unity 2021.2.8f1.

 

I also got the same problem and on several projects for 1 years

 

I also get this problem (Unity 2021.2.11). Could someone from Unity please explain what that message even means? What are preview scenes anyway?

 

I got this problem too

 

me to, started after I imported the damn text mesh stuff for the first time!

 

Same here

 

Hi, I've had the same problem in Unity 2021.1.23, I've reloaded the Layout and the problem have disappeared, hope it works for you

 

Same in 2021.3.2f1

 

Why is Unity so absent here?

 

For anyone else encountering this problem, for me it was a result of using the TextureInspector's PreviewGUI manually by calling UnityEditor.CreateEditor on a RenderTexture.
This editor's previews create some preview scenes and doesn't expose a way to clean them up when you're launching the previews externally.

Due to the fact that I didn't want to rewrite this feature from scratch, and because a large amount of functionality is locked behind internal classes which we don't have access to, I decided to use reflection to acquire the MethodInfo for TextureInspector.OnDisable and called it in the appropriate places in my editor, such as in OnDisable and some other places that made sense in the context.

Obviously this wouldn't be a supported approach and you shouldn't leverage the existing TextureInspector in this way I just don't care about dealing with the related maintenance issues.

 

I'm doing the same thing but sporadically I still get the following error:

Performance warning: There are more than 100 preview scenes. There might be code not releasing the preview scene after creating it.
UnityEditor.Texture3DPreview:OnEnable ()

Any ideas?

Thank you.

I call this wrapper from an ObjectPreview, it works well except for the above message.

Code (CSharp):

1. using System.Collections.Generic;
2. using System.Linq;
3. using System.Reflection;
4. using JetBrains.Annotations;
5. using UnityEditor;
6. using UnityEngine;
7. using UnityEngine.Assertions;
8.  
9. namespace XYZ.Editors
10. {
11.     [PublicAPI]
12.     public sealed class TexturePreview
13.     {
14.         private readonly Dictionary<Object, Texture> Dictionary = new();
15.  
16.         private Editor Editor = null!;
17.  
18.         public void Initialize(Object[] targets, System.Func<Object, Texture> func)
19.         {
20.             foreach (var target in targets)
21.             {
22.                 Dictionary.Add(target, func(target));
23.             }
24.  
25.             Assert.IsNull(Editor);
26.  
27.             Editor = Editor.CreateEditor(Dictionary.Values.Cast<Object>().ToArray());
28.  
29.             // BUG Performance warning: There are more than 100 preview scenes. There might be code not releasing the preview scene after creating it.
30.             Editor.GetType().GetMethod("OnEnable", BindingFlags.Instance | BindingFlags.NonPublic)!.Invoke(Editor, null);
31.         }
32.  
33.         public void Cleanup()
34.         {
35.             Assert.IsNotNull(Editor);
36.  
37.             // BUG Performance warning: There are more than 100 preview scenes. There might be code not releasing the preview scene after creating it.
38.             Editor.GetType().GetMethod("OnDisable", BindingFlags.Instance | BindingFlags.NonPublic)!.Invoke(Editor, null);
39.  
40.             Object.DestroyImmediate(Editor);
41.  
42.             foreach (var pair in Dictionary)
43.             {
44.                 Object.DestroyImmediate(pair.Value);
45.             }
46.  
47.             Dictionary.Clear();
48.         }
49.  
50.         public string GetInfoString()
51.         {
52.             return Editor.GetInfoString();
53.         }
54.  
55.         public GUIContent GetPreviewTitle()
56.         {
57.             return Editor.GetPreviewTitle();
58.         }
59.  
60.         public bool HasPreviewGUI()
61.         {
62.             return Editor.HasPreviewGUI();
63.         }
64.  
65.         public bool MoveNextTarget()
66.         {
67.             return Editor.MoveNextTarget();
68.         }
69.  
70.         public void OnInteractivePreviewGUI(Rect r, GUIStyle background)
71.         {
72.             Editor.OnInteractivePreviewGUI(r, background);
73.         }
74.  
75.         public void OnPreviewSettings()
76.         {
77.             Editor.OnPreviewSettings();
78.         }
79.  
80.         public Texture2D RenderStaticPreview(string assetPath, Object[] subAssets, int width, int height)
81.         {
82.             return Editor.RenderStaticPreview(assetPath, subAssets, width, height);
83.         }
84.  
85.         public void ResetTarget()
86.         {
87.             Editor.ResetTarget();
88.         }
89.     }
90. }

 

I'd suggest not doing it to be honest. I had thought I resolved the problem but ended up recreating it when using this.
I opted to make a custom UIToolkit control which has the functionality I need (selecting rendering R,G,B, and A channels)
The important part was just to call these two EditorGUI methods to draw the texture using a ColorWriteMask to pick which to call.

Code (CSharp):

1.  
2. if (previewMask == ColorWriteMask.Alpha)
3.   EditorGUI.DrawTextureAlpha(contentSize, image, ScaleMode.ScaleToFit);
4. else
5. {
6.   if (previewMask == 0) previewMask = ColorWriteMask.All;
7.   EditorGUI.DrawPreviewTexture(contentSize, image, null, ScaleMode.ScaleToFit, 0, -1, previewMask);
8. }

 

I guess you're right... Tried to track the error down, it comes from Texture3D preview internally and well, there really isn't much that one can do.

I didn't know that preview settings can be done using UI elements, have to look onto this!

Thank you.

 

I also encountered this problem, in Unity 2021.3.27. I seem to be due to MeshPreview.

 

Encountered the same issue, caused by a script that added padding to pixels of the blue channel of some Texture2D.
Unity 2022.2.1f1

 

This is an old thread, but this issue occurred this morning when I imported a large (< 10K items) asset package that creates this error every time I install it. This editor log may help (this entry is repeated many times.It may have to do with the TextureImporter not releasing the Previews? Just a guess based on the below.

Note: asset is Super_Retro_Collection from the asset store.

2024-02-02T16:47:57.752Z|0x630c|Performance warning: There are more than 100 preview scenes. There might be code not releasing the preview scene after creating it.

UnityEngine.Debug:ExtractStackTraceNoAlloc (byte*,int,string)

UnityEngine.StackTraceUtility:ExtractStackTrace ()





UnityEditor.SceneManagement.EditorSceneManager:NewPreviewScene (bool,UnityEditor.SceneManagement.PreviewSceneFlags)

UnityEditor.SceneManagement.EditorSceneManager:NewPreviewScene ()





UnityEditor.PreviewScene:.ctor (string)

UnityEditor.PreviewRenderUtility:.ctor ()

UnityEditor.GameObjectInspector/PreviewData:.ctor (UnityEngine.Object,bool)

UnityEditor.GameObjectInspector:GetPreviewData (bool)

UnityEditor.GameObjectInspector:OnPreviewGUI (UnityEngine.Rect,UnityEngine.GUIStyle)

UnityEditor.Editor:OnInteractivePreviewGUI (UnityEngine.Rect,UnityEngine.GUIStyle)

UnityEditor.ObjectPreview:DrawPreview (UnityEditor.IPreviewable,UnityEngine.Rect,UnityEngine.Object[])

UnityEditor.AssetImporters.AssetImporterEditor:DrawPreview (UnityEngine.Rect)

UnityEditor.PropertyEditor:DrawPreview (UnityEditor.IPreviewable)

UnityEditor.PropertyEditor:DrawPreviewAndLabels ()

UnityEngine.UIElements.IMGUIContainer:DoOnGUI (UnityEngine.Event,UnityEngine.Matrix4x4,UnityEngine.Rect,bool,UnityEngine.Rect,System.Action,bool)

UnityEngine.UIElements.IMGUIContainer:HandleIMGUIEvent (UnityEngine.Event,UnityEngine.Matrix4x4,UnityEngine.Rect,System.Action,bool)

UnityEngine.UIElements.IMGUIContainer:DoIMGUIRepaint ()

UnityEngine.UIElements.UIR.RenderChainCommand:ExecuteNonDrawMesh (UnityEngine.UIElements.UIR.DrawParams,single,System.Exception&)

UnityEngine.UIElements.UIR.UIRenderDevice:EvaluateChain (UnityEngine.UIElements.UIR.RenderChainCommand,UnityEngine.Material,UnityEngine.Material,UnityEngine.Texture,UnityEngine.Texture,single,System.Exception&)

UnityEngine.UIElements.UIR.RenderChain:Render ()

UnityEngine.UIElements.UIRRepaintUpdater:Update ()

UnityEngine.UIElements.VisualTreeUpdater:UpdateVisualTreePhase (UnityEngine.UIElements.VisualTreeUpdatePhase)

UnityEngine.UIElements.Panel:UpdateForRepaint ()

UnityEngine.UIElements.Panel:Repaint (UnityEngine.Event)

UnityEngine.UIElements.UIElementsUtility:DoDispatch (UnityEngine.UIElements.BaseVisualElementPanel)

UnityEngine.UIElements.UIElementsUtility:UnityEngine.UIElements.IUIElementsUtility.ProcessEvent (int,intptr,bool&)

UnityEngine.UIElements.UIEventRegistration:ProcessEvent (int,intptr)

UnityEngine.UIElements.UIEventRegistration/<>c:<.cctor>b__1_2 (int,intptr)

UnityEngine.GUIUtility:ProcessEvent (int,intptr,bool&)



[C:\build\output\unity\unity\Editor\Src\SceneManager\EditorSceneManager.cpp line 686]

 

There's also this. The GridPaintPaletteClipboard is the UIElement part of the Tile Palette which displays the palette prefab's Tilemap. This message occurs every time I do a scripting reload. Again, I have third-party palettes, two of which are about 7K tiles each. This doesn't occur when these two huge tilesets aren't present in the Project.

Perhaps it'd be better for the PaletteClipboard to do this in a more lazy fashion? IDK.

Unity 2022.2.3

It appears to be harmless but no one likes spurious error/warning messages

[./Library/PackageCache/com.unity.2d.tilemap@1.0.0/Editor/GridPaintPaletteClipboard.cs line 379]



2024-02-02T17:21:40.282Z|0x630c|Performance warning: There are more than 100 preview scenes. There might be code not releasing the preview scene after creating it.

UnityEngine.Debug:ExtractStackTraceNoAlloc (byte*,int,string)

UnityEngine.StackTraceUtility:ExtractStackTrace ()

UnityEditor.SceneManagement.EditorSceneManager:NewPreviewScene (bool,UnityEditor.SceneManagement.PreviewSceneFlags)

UnityEditor.SceneManagement.EditorSceneManager:NewPreviewScene ()

UnityEditor.PreviewScene:.ctor (string)

UnityEditor.PreviewRenderUtility:.ctor ()

UnityEditor.PreviewRenderUtility:.ctor (bool,bool)

UnityEditor.Tilemaps.GridPaintPaletteClipboard:InitPreviewUtility () (at ./Library/PackageCache/com.unity.2d.tilemap@1.0.0/Editor/GridPaintPaletteClipboard.cs:379)

UnityEditor.Tilemaps.GridPaintPaletteClipboard:OnEnable () (at ./Library/PackageCache/com.unity.2d.tilemap@1.0.0/Editor/GridPaintPaletteClipboard.cs:644)

UnityEngine.ScriptableObject:CreateScriptableObjectInstanceFromType (System.Type,bool)

UnityEngine.ScriptableObject:CreateInstance (System.Type)

UnityEngine.ScriptableObject:CreateInstance<UnityEditor.Tilemaps.GridPaintPaletteClipboard> ()

UnityEditor.Tilemaps.TilePaletteClipboardElement:OnAttachedToPanel (UnityEngine.UIElements.AttachToPanelEvent) (at ./Library/PackageCache/com.unity.2d.tilemap@1.0.0/Editor/UI/TilePaletteClipboardElement.cs:75)

UnityEngine.UIElements.EventCallbackFunctor`1<UnityEngine.UIElements.AttachToPanelEvent>:Invoke (UnityEngine.UIElements.EventBase)

UnityEngine.UIElements.EventCallbackRegistry/DynamicCallbackList:Invoke (UnityEngine.UIElements.EventBase,UnityEngine.UIElements.BaseVisualElementPanel,UnityEngine.UIElements.VisualElement)

UnityEngine.UIElements.EventDispatchUtilities:HandleEvent_BubbleUpCallbacks (UnityEngine.UIElements.EventBase,UnityEngine.UIElements.BaseVisualElementPanel,UnityEngine.UIElements.VisualElement)

UnityEngine.UIElements.EventDispatchUtilities:HandleEventAtTargetAndDefaultPhase (UnityEngine.UIElements.EventBase,UnityEngine.UIElements.BaseVisualElementPanel,UnityEngine.UIElements.VisualElement)

UnityEngine.UIElements.VisualElement:HasChangedPanel (UnityEngine.UIElements.BaseVisualElementPanel)

UnityEngine.UIElements.VisualElement:SetPanel (UnityEngine.UIElements.BaseVisualElementPanel)

UnityEngine.UIElements.VisualElement/Hierarchy:SetParent (UnityEngine.UIElements.VisualElement)

UnityEngine.UIElements.VisualElement/Hierarchy:Insert (int,UnityEngine.UIElements.VisualElement)

UnityEngine.UIElements.VisualElement/Hierarchy:Add (UnityEngine.UIElements.VisualElement)

UnityEngine.UIElements.VisualElement:Add (UnityEngine.UIElements.VisualElement)

UnityEngine.UIElements.VisualElement:Add (UnityEngine.UIElements.VisualElement)

TilePlus.Editor.Painter.TilePlusPainterWindow:CreateGUI () (at Assets/Plugins/TilePlus/Editor/Painter/TilePlusPainterWindow.cs:1820)

TilePlus.TpLib/<DelayedCallback>d__155:MoveNext () (at Assets/Plugins/TilePlus/Runtime/StaticLib/TpLib.cs:2620)

System.Runtime.CompilerServices.AsyncMethodBuilderCore/MoveNextRunner:InvokeMoveNext (object)

System.Threading.ExecutionContext:RunInternal (System.Threading.ExecutionContext,System.Threading.ContextCallback,object,bool)

System.Threading.ExecutionContext:Run (System.Threading.ExecutionContext,System.Threading.ContextCallback,object,bool)

System.Runtime.CompilerServices.AsyncMethodBuilderCore/MoveNextRunner:Run ()

System.Threading.Tasks.SynchronizationContextAwaitTaskContinuation/<>c:<.cctor>b__7_0 (object)

UnityEngine.UnitySynchronizationContext/WorkRequest:Invoke ()

UnityEngine.UnitySynchronizationContext:Exec ()

UnityEngine.UnitySynchronizationContext:ExecuteTasks ()