veiwshed error - raster has no data...  but it does really

Discussion created by kwmiller1 on Nov 9, 2010
Latest reply on Mar 29, 2013 by Akutan
I am continually getting an error trying to run a viewshed on a tiff using an observer point that matches the projection of the ratser.  However, I get the error -
error 010004 : All cells in grid <name taken away>  have the NODATA value.

Everything about my tiff looks OK, it displays, has data, seems to have the ancialry files, etc. 

Any ideas???