IExtenderSite.NotifyDelete Method (Int32)
Called by the automation extender to notify its site when it is being destroyed. If you fail to call this method, Visual Studio may crash.
Assembly: EnvDTE (in EnvDTE.dll)
The extender manager maintains an internal cache of extender objects, and must be notified when they are being destroyed. You must callimmediately upon destroying extender objects. You must not wait for the application to become idle, because other Visual Studio components may try to access the destroyed extender object before you call the method. If this happens, Visual Studio may crash.