080122 : Network Analyst extension is not enabled or not installed.

Description

ArcGIS Network Analyst extension must be installed, licensed, and activated to perform this function.

Solution

From within ArcMap, select the Tools drop-down menu, and select Extensions, then verify that the Network Analyst extension is enabled. If Network Analyst is available in the list of extensions, but is greyed out, then the license has not been activated. If Network Analyst does not appear in the list of extensions, then it must be installed. For Custom installation options, consult your ArcGIS installation document.