Steps to reproduce:
1. Create new Unity project
2. Open Multiplayer Center
3. Select Genre of the Game> Arcade, Platformer, Sandbox and Number of Players per Session > 512+
4. At the bottom right corner press “Install Packages”
5. Once installed, open Project Settings window
6. Open Multiplayer > Build
7. Expand Excluded Baking System Assemblies and Additional Scripting Defines in Client and Server sections
8. Add 22 elements in Client > Excluded Baking System Assemblies list
9. Add 22 elements in Client > Additional Scripting Defines
10. Observe Project Settings window

Actual results: Adding a larger value of elements in Multiplayer > Build window, breaks Project Settings window and “NullReferenceException: Object reference not set to an instance of an object
Unity.NetCode.Hybrid.ClientSettings+<>c.<UpdateUI>b__8_0 (UnityEngine.UIElements.ChangeEvent`1[T] evt) (at ./Library/PackageCache/com.unity.netcode@5d39c9b3860a/Runtime/Authoring/Hybrid/NetCodeClientSettings.cs:209)” error is thrown in the Console window
Expected results: Adding a larger value of elements Multiplayer > Build window, should not break Project Settings window

Reproducible with versions: 1.0.1 (6000.0.65f1, 6000.3.3f1, 6000.4.0b3, 6000.5.0a3)

Tested on (OS): macOS Tahoe 26.1 (M1), Ubuntu 24.04