Hi @Darkforce_the_ilogic_guy. Over the years of interacting with files from many different people from all over through the forums, I have noticed that the Document.DisplayName is not that stable. Not only because it is a Read/Write property, but because sometimes it seems to include file extension, and sometimes it does not. That is one of the reasons why I don't like to rely on the iProperties.Value(sDocName, sPropSetName, sPropName) iLogic snippet for accessing the iProperties of referenced documents directly. Lately, if I have a 'new' document open that has not been saved yet, it will still have a DisplayName, but no file extension yet, because it has not been saved yet, so no file yet. But after that same document has been saved, its DisplayName will then include the file extension. It seems to me like we used to have some level of control over what the DisplayName included, but I can't remember how/where.
Beyond that, here is a nice custom Function just for getting the 'Model' BrowserPane, which uses BrowserPane.BuiltIn, BrowserPane.TreeBrowser, and BrowserPane.InternalName to get the correct one, no matter which type of document it is, or what language your installation of Inventor is. You already know that when it is a Part, the InternalName for the Model browser is "PmDefault", but when it is an assembly it is "AmBrowserArrangement", and when it is a drawing it is "DlHierarchy". Just specifying "Model" works good for English language installations, but not for many other languages.
Function GetModelBrowserPane(oDoc As Inventor.Document) As Inventor.BrowserPane
For Each oPane As Inventor.BrowserPane In oDoc.BrowserPanes
If oPane.BuiltIn And oPane.TreeBrowser And _
(oPane.InternalName = "AmBrowserArrangement" Or _
oPane.InternalName = "DlHierarchy" Or _
oPane.InternalName = "PmDefault") Then Return oPane
Next
Return Nothing
End Function
Wesley Crihfield

(Not an Autodesk Employee)