"NullReferenceException" is thrown when "Affordance Theme Datum" is not set

Package: XR Interaction Toolkit

3.0.X

3.0.0

2.5.X

2.5.3

How to reproduce:
1. Open the attached project "VR-Prototyping-2.zip"
2. Enter Play Mode

Expected results: No errors are thrown in the Console window
Actual results: "NullReferenceException" is thrown

Reproducible with: 2.5.2, 3.0.0-pre.1 (2021.3.34f1, 2022.3.17f1, 2023.2.4f1, 2023.3.0b1)

Reproducible on: Windows 11 22H2
Not reproducible on: No other environment tested