Description
This tool uses functionality in the ArcGIS Network Analyst extension. You do not have a license for the Network Analyst extension or it has not been enabled.
Solution
Find an alternative approach to the analysis or purchase a license for the Network Analyst extension.
In the application, click Licensing in the Catalog pane. Verify that Network Analyst is in the Installed Extensions list. If Network Analyst is listed but is unavailable, the license has not been activated. If Network Analyst does not appear in the list of extensions, it must be installed. See the administrator of your organization for more information.