How to reproduce:
1. Create a new Unity project
2. Go to Window -> Package Management -> Package Manager -> Unity Registry -> ECS -> Install
3. In the Hierarchy, right-click on the "SampleScene" header -> New Empty Sub Scene
4. Select the created Sub Scene GameObject
5. In the Inspector, under the "Sub Scene" Component, click the "?" button and observe the results

Expected results: The documentation is opened
Actual results: The documentation is missing

Reproducible with: 1.4.4, 6.4.0, 6.5.0 (6000.0.66f1, 6000.4.0b5, 6000.5.0a5)

Reproducible on: macOS Tahoe 26 (M1)
Not reproducible on: No other environment tested