*Steps to reproduce:*
# Create a new Unity project
# Make sure the AI Assistant package/s are installed
# Click the "AI" button, which is displayed in the toolbar next to the "Unity version Control" button
# Click the "Open Assistant" option
# Verify that the window opens
# Click the "Attach" button, which is displayed at the bottom of the window
# Enter "test" into the search field in the window and click "Enter"
# Close the window
# Observe the "Console" view

*Actual results:* User gets an error "NullReferenceException: Object reference not set to an instance of an object" in the Console window. A short video is added below in the "Attachment" area.

*Expected results:* No errors

*Reproducible with versions:* 1.0.0-pre.3 (6000.2.0b1)

*Not reproducible with versions:* -

*Can’t test with versions:* -

*Tested on (OS):* M1 Max - Sequoia 15.4.1

*Notes:* Full error

NullReferenceException: Object reference not set to an instance of an object
Unity.AI.Assistant.UI.Editor.Scripts.Utils.PopupTracker.Dispose () (at ./Library/PackageCache/com.unity.ai.assistant@95cd11640ec5/Editor/UI/Scripts/Utils/PopupTracker.cs:97)
Unity.AI.Assistant.UI.Editor.Scripts.Components.AssistantView.HideSelectionPopup () (at ./Library/PackageCache/com.unity.ai.assistant@95cd11640ec5/Editor/UI/Scripts/Components/AssistantView.cs:583)
Unity.AI.Assistant.UI.Editor.Scripts.AssistantWindow.OnLostFocus () (at ./Library/PackageCache/com.unity.ai.assistant@95cd11640ec5/Editor/UI/Scripts/AssistantWindow.cs:50)
UnityEditor.HostView.OnLostFocus () (at /Users/bokken/build/output/unity/unity/Editor/Mono/HostView.cs:355)
UnityEditor.DockArea.OnDestroy () (at /Users/bokken/build/output/unity/unity/Editor/Mono/GUI/DockArea.cs:141)
UnityEditor.ContainerWindow:RequestCloseSentByNativeCode() (at /Users/bokken/build/output/unity/unity/Editor/Mono/ContainerWindow.cs:443)