The tool requires a Spatial Analyst extension license. These are conditions where a license may not be available:
- The extension was not installed.
- The extension was not enabled.
- There is not a license available to be checked out for use.
The following solutions correspond to the conditions listed:
- Install the extension. Consult the ArcGIS installation guide or contact your system administrator.
- Check the Use extensions section of the help for assistance with activating the extension.
- If Spatial Analyst has been enabled, other users on your network may be using all the available licenses. You could see whether someone who is not actively using the extension can close their session. If this is a frequent occurrence, you could consider acquiring more licenses.
If you are trying to run Spatial Analyst in a script, use the CheckOutExtension function for more information on how to obtain licenses in your code.