NullReferenceExceptions are thrown if clicking inside a window that contains Overlays while entering Play mode

Steps to reproduce:

1. Open the attached project
2. Open the Scene View window
3. Press the Enter Play Mode button
4. While the Editor is loading the Play mode, click a few times inside the Scene view

Actual results: NullReferenceExceptions are thrown in the Console window

Expected results: No errors are thrown in the Console if the user clicks inside the Editor while it is loading the Play mode

Reproducible with versions: 6000.5.0a1, 6000.5.0a5

Not reproducible with versions: 6000.0.66f1, 6000.3.5f1, 6000.4.0b5

Reproducible on (OS): macOS 26.2

Not reproducible on (OS): Ubuntu 22

Notes:

• The issue did not reproduce on the Ubuntu 22 machine
• Only managed to reproduce when clicking in the Scene and Tile Palette windows. Both windows contain Overlays

 

Full error message:

NullReferenceException: Object reference not set to an instance of an object
UnityEngine.IMGUITextHandle.IsAdvancedTextEnabled () (at /Users/bokken/build/output/unity/unity/Modules/IMGUI/IMGUITextHandle.cs:429)
UnityEngine.TextEditor.get_emptyString () (at /Users/bokken/build/output/unity/unity/Modules/IMGUI/TextEditor.cs:81)
UnityEngine.TextEditor.get_textWithWhitespace () (at /Users/bokken/build/output/unity/unity/Modules/IMGUI/TextEditor.cs:87)
UnityEngine.TextEditor..ctor () (at /Users/bokken/build/output/unity/unity/Modules/IMGUI/TextEditor.cs:147)
UnityEditor.EditorGUI+RecycledTextEditor..ctor () (at <ecd5d9b2a07c4921893da9fdbb81dead>:0)
UnityEditor.EditorGUI+DelayedTextEditor..ctor () (at /Users/bokken/build/output/unity/unity/Editor/Mono/EditorGUI.cs:602)
UnityEditor.EditorGUI.get_s_DelayedTextEditor () (at /Users/bokken/build/output/unity/unity/Editor/Mono/EditorGUI.cs:38)
UnityEditor.HandleUtility.BeginHandles () (at /Users/bokken/build/output/unity/unity/Editor/Mono/Handles/HandleUtility.cs:760)