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Steps to reproduce:
1. Create new Unity project using Universal 3D Template
2. Install AI package via “AI” toolbar button
3. Open Standalone Profiler
4. Profile in Edit Mode for few seconds and select CPU or GPU frames
5. Open Package Manager window
6. Find and remove Assistant package
7. Go back to Standalone Profiler, press “Ask Assistant” button
Actual results: “ArgumentNullException: Value cannot be null.” and “NullReferenceException: Object reference not set to an instance of an object” errors are thrown in the Console when pressing “Ask Assistant” button in Standalone Profiler when Assistant package is deleted
Expected results: “Ask Assistant” button should disappear from Standalone Profiler once Assistant package is deleted, no errors thrown in the Console window
Reproducible with versions: 2.9.0-pre.1 (6000.4.9f1, 6000.5.0b10, 6000.6.0a4)
Tested on (OS): Windows 11, macOS Tahoe 26.4.1
Notes:
Internal error - unexpected guid mismatch UnityEditor.ScriptableSingleton`1<Unity.AI.Assistant.UI.Editor.Scripts.AssistantUISessionState>:get_instance () Unity.AI.Assistant.UI.Editor.Scripts.AssistantBlackboard:SaveContextState () (at ./Library/PackageCache/com.unity.ai.assistant@66208e716584/Editor/UI/Scripts/AssistantBlackboard.cs:268) Unity.AI.Assistant.UI.Editor.Scripts.AssistantBlackboard:AddVirtualAttachment (Unity.AI.Assistant.VirtualAttachment) (at ./Library/PackageCache/com.unity.ai.assistant@66208e716584/Editor/UI/Scripts/AssistantBlackboard.cs:222)
Failed to Load Asset: Packages/com.unity.ai.assistant/Editor/UI/Views/PromptPopupView.uxml UnityEngine.Debug:LogErrorFormat (string,object[]) Unity.AI.Assistant.UI.Editor.Scripts.Utils.UXLoader:LoadAsset<UnityEngine.UIElements.VisualTreeAsset> (string,UnityEngine.UIElements.VisualTreeAsset&,bool) (at ./Library/PackageCache/com.unity.ai.assistant@66208e716584/Editor/UI/Scripts/Utils/UXLoader.cs:32) Unity.AI.Assistant.UI.Editor.Scripts.Utils.ViewCache:Load (string) (at ./Library/PackageCache/com.unity.ai.assistant@66208e716584/Editor/UI/Scripts/Utils/ViewCache.cs:71)
ArgumentNullException: Value cannot be null. Parameter name: styleSheet UnityEngine.UIElements.VisualElementStyleSheetSet.Insert (System.Int32 index, UnityEngine.UIElements.StyleSheet styleSheet) (at <ed012843806d484ebbbf17a18389d56a>:0) UnityEngine.UIElements.VisualElementStyleSheetSet.Add (UnityEngine.UIElements.StyleSheet styleSheet) (at <ed012843806d484ebbbf17a18389d56a>:0) Unity.AI.Toolkit.Accounts.Components.BasicBannerContent.Init () (at ./Library/PackageCache/com.unity.ai.assistant@66208e716584/Modules/Unity.AI.Toolkit.Accounts/Components/SessionStatusBanner/Content/BannerContent.cs:93)
NullReferenceException: Object reference not set to an instance of an object
Unity.AI.Assistant.UI.Editor.Scripts.Components.AssistantView.UnregisterContextCallbacks () (at ./Library/PackageCache/com.unity.ai.assistant@66208e716584/Editor/UI/Scripts/Components/AssistantView.Context.cs:38)
Unity.AI.Assistant.UI.Editor.Scripts.Components.AssistantView.Deinit () (at ./Library/PackageCache/com.unity.ai.assistant@66208e716584/Editor/UI/Scripts/Components/AssistantView.cs:373)
Unity.AI.Assistant.UI.Editor.Scripts.AssistantWindow.OnDestroy () (at ./Library/PackageCache/com.unity.ai.assistant@66208e716584/Editor/UI/Scripts/AssistantWindow.cs:178)
UnityEditor.ContainerWindow:RequestCloseSentByNativeCode()
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