changing raster symbology causes crash

Discussion created by douglaspatton on Jun 6, 2011
I've attached a picture with the problem. 

I've created the raster map by taking a Fish and Wildlife Service National Wildlife Refuge boundary layer, creating a new layer from certain selected elements, then clipping a NLCD 2006 land class map by the new layer of selected elements.

when trying to use ARCSCAN to vectorize the resulting raster (the regular tool in the toolbox takes forever and returns errors), I must first change the symbology from colormap to unique values.  For some of the rasters created in this manner there is no problem, but for others, I get the runtime error shown in the attached image.