I am running on an install of ArcGIS Desktop 10.6 ArcInfo Licence. I am not seeing the Calculate Geometry Attributes tool in the toolbox under Data Management Tools-->Features Toolset-->Calculate Geometry Attributes. I am also getting an error in the Python console in Desktop when I try to execute the tool out of the Arcpy module. According to the help page, this should have come with ArcGIS Desktop 10.6. Am I missing something?
Help Page: Calculate Geometry Attributes—Help | ArcGIS Desktop
Glad I found this! It saved me further frustration. Hope the leg is better Mike.
Cheers
Pat