It looks like you have ‘Start Panel’ pointing to itself. Not sure of your setup but this could be causing some logic issues :
StartPanelBroo = StartPanel has StartPanelBroo = StartPanel has StartPanelBr… and so on.
or depending on the script, it could be looking for a GameObject in the Scene, and possibly you assigned a prefab from the Project, so it’s no where to be found in the scene.
maybe you are just losing your reference to your gameobject. by having something like StartPanelBROO = null;