An error was encountered when converting a shapefile to a grid. When converting polygons to a raster, the internal mechanism determines the geometry by intersecting the polygons with lines. It is expected that wherever a line intersects a polygon shape, an even number of intersection points is found. However, in this case, an odd number of intersections was calculated. This may be a result of bad data or an algorithm failure.
Make sure the polygon shapefile is valid. You can use Check Geometry to inspect the dataset for problems. If the data is seemingly valid, it might represent a case that cannot be handled by the conversion algorithm. In this case, please contact ESRI Technical Support.