Get the list of all the feature name in MFG model using vb.net

hi,

I would like to list down all the feature available in the model I have used following code.

modelitems = CType(mdel, IpfcModelItemOwner).ListItems(EpfcModelItemType.EpfcITEM_FEATURE)

the above code works fine if part is in the session,

but I get a error message when MFG model is in the session.

request support to solve the above problem please

Paulson E