Problem: Commands added to the toolbar are not enabled
When you open the Customize dialog and drag commands from a Context Menu onto a toolbar, most of those commands are disabled.
Some commands are designed to work only on context menus and will be enabled only when a particular condition has been met. For example, when you right-click a Layer in an ArcMap DataFrame, the Feature Layer Context Menu pops up and the Zoom To Layer command is enabled.
Other commands appear not only on a context menu but also on a toolbar. These commands will be enabled once the prerequisite conditions are met. For example, open the Customize dialog box and click Context Menus. From the Feature Layer Context Menu, drag the Add Data command to a Toolbar. Add Data will be enabled.
Solution or Workaround
Make sure you meet the requirements that will enable the command. Remember, some commands are designed to reside only on a Context Menu. Fewer commands are designed to reside on both a Context Menu and on a toolbar.