I am running a code that uses arcpy.sa.ExtractByMask but it returns: ExecuteError: Failed to execute. Parameters are not valid. ERROR 000824: The tool is not licensed. Failed to execute (ExtractByMask) I know i have spatial analyst licensed and the tool works fine within arcmap itself. Anyone ever come across this? Edit: arcpy.CheckExtension('Spatial') returns 'Available' The code I am trying to run is: # """folder containing only your input rasters and nothing else""" indir = 'D:\Sheyenne\Atmospherically Corrected Landsat\Practice_bands' """absolute path to your mask layer""" mask = 'D:\Sheyenne\Sheyenne_area.shp' """create emply list to hold paths to input rasters""" inrasters = [] """populate the list inrasters with all paths to .tif in directory""" os.chdir(indir) for r in glob.glob('*.tif'): inrasters.append(r) """iterate over all input .tif from list inrasters""" for inraster in inrasters: """create a unique name for each output raster""" outraster = inraster.replace('.tif','_clip.tif') """Clip each raster with it's unique name as output""" arcpy.gp.ExtractByMask_sa('inraster','mask') The snippet when I run the tool in arcmap is: arcpy.gp.ExtractByMask_sa("LT50290282011268PAC01_sr_band1.tif", "sheyenne_area_poly", "D:/Sheyenne/Atmospherically Corrected Landsat/Practice_band_clip/p1") Note that the code is using a loop to execute extract by mask for multiple images while the snippet is the tool for just 1 image.