UccApi Dll (Microsoft.Office.Interop.UccApi.Dll) not workiing properly prevents code from being executed VB.NET

See the code below:

For some strange reason the second MessageBox is never shown. What I get is an MSI installer popup asking for a file. The breakpoint is never reached.

That happens after Me.platform = New UccPlatform(). Currently I am in the dll with the Microsoft (R) .NET Framework IL Disassembler. I am looking for the constructor of UccPlatform which I am unable to locate.

Does somebody have an explanation. If I need to rebuild the Microsoft.Office.Interop.UccApi.Dll how do I do that since it is from Microsoft? Can I download a newer version (latest build) from Microsoft? If so from what URL?

Did I not correctly register the DLL - how can I check that? I found "Class not registered (Exception from HRESULT: 0x80040154 (REGDB_E_CLASSNOTREG))" on how to register a DLL.

Imports Microsoft.Office.Interop.UccApi

Class MainWindow
    Private platform As IUccPlatform
    Private Sub Button_Click_1(sender As Object, e As RoutedEventArgs)
        MessageBox.Show("Hello World")
        Me.platform = New UccPlatform()
        MessageBox.Show("Welcome to the platform") 
    End Sub
End Class