Addon.Enabled Property (Visio)
Determines whether or not an Addon object is currently enabled. Read/write.
expression A variable that represents an Addon object.
An add-on implemented by an executable (EXE) file always reports itself as enabled. An add-on implemented by a Visio Solutions Library (VSL) file reports itself as enabled or disabled according to the enabling policy that the VSL file has registered for that add-on.
You cannot tell an add-on to enable or disable itself. Visio will not send a run message to a disabled add-on. If an add-on is disabled, its name appears unavailable in the Visio user interface.