“The referenced script (Unknown) on this Behaviour is missing!” warnings, and “ScriptableSingleton already exists” errors are thrown when Adaptive Performance is disabled in Play Mode

Steps to reproduce:

1. Create a new Unity project using the Universal 3D template
2. Open the Project Setting window (Edit > Project Settings)
3. Open the Adaptive Performance tab
4. Enable Adaptive Performance
5. Enable "Basic Provider", and "Device Simulator Provider"
6. Enter Play Mode
7. Disable Adaptive Performance
8. Exit Play Mode
9. Observe the Console window
10. Repeat step 6, 8, 9

Actual results: “The referenced script (Unknown) on this Behaviour is missing!” warnings, and “ScriptableSingleton already exists” errors are thrown

Expected results: No warnings or errors thrown

Reproducible with versions: 6000.3.7f1, 6000.4.0b7, 6000.5.0a6

Can’t test with versions: 6000.0.66f1 (due to no enable/disable functionality of Adaptive Performance)

Tested on (OS): MacOS Silicon Tahoe 26.2