Unlock Object

I am working with an editable map that has a zip code layer with fill and stroke but for some reason I cannot select one of the polygons - or change the fill or stroke color - in the zip code layer. I tried unlocking the page ctrl-alt-2 and unlocking any masks ctrl-alt-7. In the unedited file (I'm working with a copy) that zip code polygon is still editable. Thanks in advance, MasterG

What does the Layer Palette say? Can you go through any of this layer and see the hierarchy of the layer.