Odd Black Window

I'm working on a part.  I meant to create a new plan and drag in a DWG file to that plane, but I forgot to and SW thought I was dragging it to a non-planar feature of my part.  Now this black box has opened up and it's covering my part.  I can't figure out what it is or how to get rid of it.  Thanks to anyone who can help.

SolidworksGeneral