The Add Basemap option is missing in ArcMap

Description

When attempting to add a basemap in ArcMap from File > Add Data or from the Add Data  drop-down menu, the Add Basemap option does not appear, and a red circle icon is displayed with the word, '[ Missing ]', preventing users from adding basemaps.
 

Cause

This issue occurs when the Microsoft .NET Framework installed on the machine is not enabled when using ArcMap.

Note:
The .NET Framework version installed on the machine is specific to the version of ArcMap. For more information, refer to the supported platforms section on the ArcGIS for Desktop System Requirements page.

Solution or Workaround

1. Close ArcMap.
2. Go to Start > Control Panel > Programs and Features.
3. Click Turn Windows Features on or off.
4. Enable the Microsoft .NET framework by checking the box next to the framework name, and click OK.

5. When Windows completes the updating process, reopen ArcMap, and the Add Basemap option displays as expected.