In system add-ins typically exists the statement:

Imports TeraDP.GN4.Schema.Class

This allows to define calls such as:

Dim obj As pageObj = New pageObj(login.Schema)

If you try this in any custom add-in, you will get an error.

Error        4        Type 'pageObj' is not defined.        

C:\tera\GN4\rel6\src\GN4AddIns\FredCustomAddIn\CustomPage.vb        120        18        

FredCustomAddInExpress

Use the full path, e.g.:

Dim obj As TeraDP.GN4.Schema.Class.pageObj = New TeraDP.GN4.Schema.Class.pageObj(login.Schema)

The full path is needed as in the standard distribution, the custom add-ins do not have a required Import statement. You can surely add one, e.g. add the import statement on top of the custom add-in:

Imports TeraDP.GN4.Schema.Class

and then you can use the short variant of the call also there.