Steps to reproduce:

1. Create a new project using Universal 3D template
2. Install ECS features package
3. In the Hierarchy, right-click > New Sub Scene > Empty Scene... 
4. Save the Scene
5. Go to Window > Entities > Systems
6. Click on the "+" button in the search bar
7. Select "Parent" query block
8. Observe the Console

Actual results: "Exception: Object reference not set to an instance of an object: Failed to execute UnityEditor.Search.QueryFilterOperator handler with InitializationSystemGroup Comp: 0 Dep: 0 and Unknown" error is thrown

Expected results: no errors

Reproducible with versions: 6000.5.0a6

Can’t test with versions: 6000.0.66f1, 6000.3.8f1, 6000.4.0b8, 6000.5.0a5 (quick search not available)

Tested on (OS): Windows 11