Errors are logged continuously in the Player when PanelSettings is created at runtime

How to reproduce:

1. Open the attached "IN-150816" project
2. Open the “Main” scene
3. In the top-left corner of Unity editor, click “File” > “Build Profiles”
4. In the “Build Profiles” window, select the “Windows” platform profile > enable “Development Build”
5. In the “Build Profiles” window, click “Build and Run” and save your build
6. In the Player window next to the “Development Console”, click “Open Log File” button
7. Observe the results in the “Player.log”

Actual result: Errors are logged continuously for as long as the player runs
Expected result: The panel from the runtime-created “PanelSettings” is created and no errors are logged in the “Player.log”

Reproducible with: 6000.5.0a9 (253a859729df), 6000.5.9f1, 6000.6.0b9, 6000.7.0a4
Not Reproducible with: 6000.0.1f1, 6000.0.81f1, 6000.3.22f1, 6000.5.0a8, 6000.7.0a5
Fixed in: 6000.7.0a5

Reproducible on: Windows 11 Enterprise (25H2)
Not Reproducible on: No other environments tested

Workaround: In Assets folder, create “Resources” folder. In the “Resources” folder > right-click > “Create” > “UI Toolkit” > “Panel Settings Asset” and change “doc.panelSettings = ScriptableObject.CreateInstance<PanelSettings>()” with “doc.panelSettings = Resources.Load<PanelSettings>("PanelSettings");” in the “UitkSpawner.cs”

Notes:

• Error in log file: “NullReferenceException: Object reference not set to an instance of an object”
• Error in log file: “ICU Data not available. The data should be automatically assigned to the PanelSettings in the editor if the advanced text option is enable in the project settings. It will not be present on PanelSettings created at runtime, so make sure the build contains at least one PanelSettings asset”
• Error in log file: “UnityException: FindObjectsOfTypeAll can only be called from the main thread.”