My featureManager design tree "Material" icon has no materials listed below or RMB "Edit Material" choice 

"right-click Material in the FeatureManager design tree, and select Edit Material."

It used to show materials below and a "Edit Material" option so I don't know what happened that there are no material listings below in material icon and when I RMB it I only get the following choices "Hide/Show Tree Items..., Collapse Items & Custom Menu"

Can anyone help me get this functionally turned back on?

TIA