After creating an Add-In with Toolbar, Menu and Extension objects and doing Add From File... in the Customize dialog box only Toolbar and Menu objects are available. The Added Objects dialog after installing is shown below, note that no Extensions are listed (x.EsriAddin attachment).
[ATTACH=CONFIG]27418[/ATTACH]
The Toolbar and Menu objects can be accessed and added from the Customize dialogue, as is expected, but the Extension does not show in the Extensions dialog:
[ATTACH=CONFIG]27422[/ATTACH]
I have tried the add-in extension example specified in the docs, with the same result. This example only contains an Extension, which causes the Added Objects dialog box to show the following (arcAddin.EsriAddin attachment):
[ATTACH=CONFIG]27419[/ATTACH]
As above the Extensions dialog does not show the Add-In Extension...
I have attached the corresponding files, as specified above.
System Specs:
ArcGIS 10.1 Desktop, SP1, 64bit Background Geoprocessing, Windows XP SP3