Spatial Analyst output raster contains no values when mask has a different projection than data frame

Description

The output raster from a Spatial Analyst function contains no values when the mask is set to one particular spatial reference and the data frame is set to another.

Cause

Masks do not handle reprojection in ArcGIS 8.1.

Solution or Workaround

• Reproject the mask dataset to have the same projection as the data frame.
• Set the data frame projection to be the same as that of the mask.