After you enter Play Mode in Unity, and press the "CloseMenu" On "VRChat Client Simulator", the camera stop working therefore the screen shows "Display 1 No cameras rendering".
I have no idea how to reproduce this bug, but I heard (not sure) that it may be cause by gameobject with UdonBehaviour attached is Instantiated in a public event.
Downgrade to SDK 3.5.1, it works again.