Steps to reproduce:
1. Create new Unity project
2. Install Entities and Entities Graphics package via Package Manager
3. In Hierarchy create a New Sub Scene
4. Open Entities Hierarchy window and dock it next to Game Tab (Window > Entities > Hierarchy)
5. Select “New Sub Scene” GO in Hierarchy window
6. In Inspector window > Sub Scene Component select “Scene Asset”
7. In “Select Scene Asset” window select “SampleScene” Scene
8. In “Convert to Sub Scene” pop-up select “Convert”
9. Observe the Console window 

Actual results: “InvalidOperationException: Trying to set the parent for HierarchyNodeHandle(Kind:SubScene, Index:1, Version:0) as itself.” errors are spammed in the Console after selecting “SampleScene” Scene

Expected results: No errors are spammed in the Console window after selecting “SampleScene” Scene

Reproducible with versions: 6000.0.66f2, 6000.3.8f1, 6000.4.0b8, 6000.5.0a6

Tested on (OS): macOS Silicon Tahoe 26.2 (M1)