"InvalidOperationException: Cannot modify VisualElement hierarchy during layout calculation" error thrown after creating a Mixed Reality project

Unity: Settings Window Framework

This issue has been closed as a duplicate of:

Changing editor theme causes InvalidOperationException

Open

6.1.X

Fixed

6.2.X

6000.2.0a8

Steps to reproduce:
1. Create a new project using Mixed Reality template
2. Observe the Console

Create a new project using Mixed Reality template
Click Fix in the Project Validation Window
Observe the Console

Actual results: "InvalidOperationException: Cannot modify VisualElement hierarchy during layout calculation" and "NullReferenceException: Object reference not set to an instance of an object" errors are thrown
Expected results: No errors or warnings are thrown

Reproducible with versions: 6000.2.0a4
Not reproducible with versions: 6000.0.39f1, 6000.1.0b7, 6000.2.0a3
Can't test with versions: 2021.3.49f1 (No Mixed Reality template present)

Tested on (OS): macOS Sequoia 15.3 (M1), macOS Sequoia 15.2 (Intel)

Notes:

Issue is reproducible on macOS Sequoia 15.2 (Intel) after "Fix All" button is pressed on Project Validation window
Issue is also sometimes reproducible on macOS Sequoia 15.2 (Intel) after deleting Mixed Reality template from Library/Application Support/UnityHub/Templates path, deleting Editor version, redownloading deleted version and repeating the reproduction steps
Full errors:

InvalidOperationException: Cannot modify VisualElement hierarchy during layout calculation
UnityEngine.UIElements.VisualElement+Hierarchy.Clear () (at /Users/bokken/build/output/unity/unity/Modules/UIElements/Core/VisualElementHierarchy.cs:673)
UnityEngine.UIElements.VisualElement.Clear () (at /Users/bokken/build/output/unity/unity/Modules/UIElements/Core/VisualElementHierarchy.cs:256)
UnityEditor.SettingsWindow.ProviderChanged (UnityEditor.SettingsProvider lastSelectedProvider, UnityEditor.SettingsProvider newlySelectedProvider) (at /Users/bokken/build/output/unity/unity/Editor/Mono/Settings/SettingsWindow.cs:276)
UnityEditor.SettingsTreeView.SelectionChanged (System.Collections.Generic.IList`1[T] selectedIds) (at /Users/bokken/build/output/unity/unity/Editor/Mono/Settings/SettingsTreeView.cs:66)
UnityEditor.SettingsTreeView.FocusSelection (System.Int32 selectedId) (at /Users/bokken/build/output/unity/unity/Editor/Mono/Settings/SettingsTreeView.cs:46)
UnityEditor.SettingsWindow.SelectProviderByName (System.String name, System.Boolean ignoreLastSelected) (at /Users/bokken/build/output/unity/unity/Editor/Mono/Settings/SettingsWindow.cs:111)
UnityEditor.SettingsWindow.RestoreSelection () (at /Users/bokken/build/output/unity/unity/Editor/Mono/Settings/SettingsWindow.cs:242)
UnityEditor.SettingsWindow.InitProviders () (at /Users/bokken/build/output/unity/unity/Editor/Mono/Settings/SettingsWindow.cs:168)
UnityEditor.SettingsWindow.DrawTreeView () (at /Users/bokken/build/output/unity/unity/Editor/Mono/Settings/SettingsWindow.cs:500)
UnityEngine.UIElements.IMGUIContainer.DoOnGUI (UnityEngine.Event evt, UnityEngine.Matrix4x4 parentTransform, UnityEngine.Rect clippingRect, System.Boolean isComputingLayout, UnityEngine.Rect layoutSize, System.Action onGUIHandler, System.Boolean canAffectFocus) (at /Users/bokken/build/output/unity/unity/Modules/UIElements/Core/IMGUIContainer.cs:403)
UnityEngine.GUIUtility:ProcessEvent(Int32, IntPtr, Boolean&) (at /Users/bokken/build/output/unity/unity/Modules/IMGUI/GUIUtility.cs:219)

"InvalidOperationException: Cannot modify VisualElement hierarchy during layout calculation" error thrown after creating a Mixed Reality project

Unity: Settings Window Framework

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Fixed

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"InvalidOperationException: Cannot modify VisualElement hierarchy during layout calculation" error thrown after creating a Mixed Reality project

Unity: Settings Window Framework

Statuses

Open

Fixed

Resolution Notes

Description

Prioritise and Follow this issue

Have a workaround or additional info about this issue?