ATTACH MATERIAL BY LAYER

[CADEngr2014]

Hello,

I am running AutoCAD 2014.

I want to attach a material by layer.  I have an xref aerial image.  When I select the attach material by layer command from ribbon, the left side of the mapper shows the image name, but the "tile" does not represent the image that is referenced, it is just a grey tile.  It appears that AutoCAD is not "pulling-in" the material representing my xref image.  What am I likely missing; to get the xref aerial image as material to attach to layer?