I needed to extend the solution file of my existing application with the following section:
GlobalSection(ExtensibilityGlobals) = postSolution
Everything is working now :-)
Thank you very much
GlobalSection(ExtensibilityGlobals) = postSolution
RootNamespace = YourNamespaceComesHere
CommonProjectGuid = B4216841-2D76-4D7D-B3D2-14A2EF8268FE <- Infrastructure.Interface Project Id
ShellProjectGuid = AD29D932-7ACE-4AB0-85F1-160E6E1AB7EA <- Shell Project Id
EndGlobalSectionEverything is working now :-)
Thank you very much