How to create association for a shape using API in c#?

Dear EBDN Community,

How can we create association for a shape ?
I used this code "m_myApplication.Selection[0].TargetAssociations.Add(AssociationRole.CatalogToProject, objectItem)" to create.
But it is giving following exception to me:
Aucotec.EngineeringBase.Client.MethodNotAllowedException.
Any help would be highly appreciated.

Thanks!

Kind Regards,
Surti