*Steps to reproduce:*

1. Open attached project

2. Open the scene Assets/Room01.unity. In the Lighting window's Probe Volume tab, you'll see the Baking Set labeled "Room01 Baking Set." Additionally, observe that some indirect lighting has been baked into the APV, even though the directional light and sky are turned off, as this scene is intended to be loaded additively with Main.unity.

3. Open scene Assets/Room02.unity (not additively), same as Room01, observe the Baking Set "Room02 Baking Set" and the baked indirect lighting.

4. Open the Assets/Main.unity scene, and load additively Room01.unity. 

*Actual results:* Note that "Room02 Baking Set" is still assigned in the Lighting window's Probe Volume tab, even though Room01 is clearly receiving the correct indirect lighting from the Room01 Baking Set. The lighting visible in the viewport does not match the active Baking Set displayed. 

*Expected results:* The displayed Baking Set and the lighting in the viewport should align. If the Lighting window shows "Room02 Baking Set," the MeshRenderers from Room01 should receive incorrect lighting (from Room02). Ideally, when Room01.unity is loaded additively, it should automatically assign the correct Baking Set and reflect it in the Lighting window.

!image-2024-10-23-18-42-52-150.png!

5. Open additively Room02.unity. Try switching between the multiple Baking Sets in the Lighting window's Probe Volume tab.

*Actual results:* Nothing Happens, the lighting in the viewport is still using the Room01 Baking Set regardless of the Baking Set chosen in the Lighting Window..

*Expected results:* When multiple scenes with different Baking Sets are loaded additively, users should have the option to select which Baking Set is active. Currently, the option is here but does not work

6. Enable the GameObject "ForceRoom02_bakingSet" in the Main.unity scene. Look at the "SetBakingSet" script to notice it should use the 
"ProbeReferenceVolume.instance.SetActiveBakingSet(bakingSet);" function to switch the Baking Set by script at start.
*Actual results:*  There is an error in the console 'Null Reference Exception", and Unity crashes
!image-2024-10-23-18-51-33-232.png!

*Expected results:* Users can use the API to change the active Baking Set at runtime without error or crashes.

*Reproducible with versions:* 

*Not reproducible with versions:* 

*Can’t test with versions:* 

*Tested on (OS):* 

*Notes:*
*