The Assets/InfinityPBR/---Game Modules/_Required Prefabs folder has various prefabs which should be included in all of your scenes. These are the objects that allow the runtime scripts to access the Scriptable Objects and operate mostly autonomously.
Do Not Destroy On Load
These prefabs have a Do Not Destroy On Load component attached. Best to add them to all of your scenes -- the objects will be destroyed on load if one already exists.
Version 4.0.2 updated the "Repositories" to remove many previously required objects.