Dept. of Subtle - No Edit Family Option?

Received a query today about a project that wouldn't offer their users the Edit Family option when they selected a window or door tag family. Turns out that the project file in use was a pretty old file that had been upgraded for many releases of Revit. The option to initiate editing a family from within the project hasn't always been available to us.

When it did become available there was a requirement that any families created in earlier releases had to be upgraded to the current release before the Edit Family feature would become available. The issue was that the window and door tags had never been upgraded and reloaded. When newer versions were loaded to replace the existing ones the good old Edit Family button returned!