VERIFIED SOLUTION i

Opening a BIL file in MapInfo Pro Advance as a continuous raster for use with the Classify tool

products affected: MapInfo Pro™
Some .BIL files open within MapInfo Pro and are not recognized as having the proper data to use in the Raster Operations>Classify dialog.

The .BIL driver within MapInfo Pro sees the image as a grey scale image.   Image files are not recognized as a raster source type within the Classify tool. 

One easy workaround is to open the *.HDR file in notepad, or other text editor, by right-clicking on the file and choosing "open with" and select Notepad to open the file.

Then, edit the *.HDR file and add the following line at the bottom of the items listed: 

FIELDTYPE CONTINUOUS 

That line will be passed to the MapInfo Pro .BIL driver which will load the file as a "Continuous" field rather than an "Image".  Without that information, there is no way for the driver to tell the difference in many cases. 

Reload the raster which should now work within the Classify tool.
UPDATED:  March 18, 2019