Hmmm.... I added to tool as Dan suggests, but am now confronted with a different issue. The tool remains grayed out and the mouse-over tip says:
This command is currently disabled.
Available with Location Referencing License
Yet another license to do day to day work?
edited after a google search.... Apparently one needs the ArcGIS Pipeline Referencing Extension now to perform LRS functions....
That should just about do it....