VB.NET Parameter is not valid - vb.net

Question

I have used dotnetbar devcomponents advanced treeview to create multiple directory trees for one of my projects. Functionality wise, everything is working fine.
I have now added images to the directory file nodes (e.g. pdf image if its a pdf file) and published the application. The application runs without any errors first time on any machine, but once I close this File Management form (I have a control panel form with buttons that is the initial startup form. The buttons take me to other forms. On button click, it hides the control panel and displays the corresponding form through showdialog - File Management form is one of those buttons) and reopen it again - I get the following error:
parameter_is_not_valid
It then fails to load the nodes and after a couple of tries, Microsoft .Net Framework window appears and ends the application.
I get the images from my resource file. Please see the code for LoadAllSubDirectoriesFiles where the error occurs:
Private Sub LoadAllSubDirectoriesFiles(ByVal uParent As DevComponents.AdvTree.Node)
' Initialise Error Checking
Dim uStackframe As New Diagnostics.StackFrame
Dim ufile As IO.FileInfo = Nothing
Try
If uParent.Name.Length <> 248 Then
Dim files As IO.FileInfo() = uParent.Tag.GetFiles()
For Each file As IO.FileInfo In files
If (Not file.Attributes.ToString.Contains("Hidden")) Then
Dim uNode As DevComponents.AdvTree.Node = New DevComponents.AdvTree.Node()
uNode.Tag = file
uNode.Name = file.FullName.ToLower
uNode.Text = file.Name
If file.Extension = ".msg" Then
uNode.Image = My.Resources.Resources.Mail3
ElseIf file.Extension = ".txt" Then
uNode.Image = My.Resources.Resources.Document
ElseIf file.Extension = ".pdf" Then
uNode.Image = My.Resources.Resources.pdf
ElseIf file.Extension = ".doc" OrElse file.Extension = ".docx" Then
uNode.Image = My.Resources.Resources.doc
ElseIf file.Extension = ".xlsx" Then
uNode.Image = My.Resources.Resources.excel
ElseIf file.Extension = ".pub" Then
uNode.Image = My.Resources.Resources.publisher
ElseIf file.Extension = ".pptx" Then
uNode.Image = My.Resources.Resources.powerpoint
ElseIf file.Extension = ".bmp" OrElse file.Extension = ".png" OrElse file.Extension = ".jpg" OrElse file.Extension = ".gif" OrElse file.Extension = ".tif" Then
uNode.Image = My.Resources.Resources.bitmap_image
ElseIf file.Extension = ".zip" OrElse file.Extension = ".rar" Then
uNode.Image = My.Resources.Resources.zip
Else
uNode.Image = My.Resources.Resources.unknown
End If
uNode.DragDropEnabled = True
uParent.Nodes.Add(uNode)
End If
Next
End If
Catch ex As Exception
' Catch Error
If Err.Number <> 0 Then
WriteAuditLogRecord(uStackframe.GetMethod.DeclaringType.FullName, uStackframe.GetMethod.Name.ToString, "Error", ex.Message & vbCrLf & vbCrLf & ex.StackTrace, 0)
MsgBox("System Error Ref: " & sAuditID & vbCrLf & uStackframe.GetMethod.DeclaringType.FullName & " / " & uStackframe.GetMethod.Name.ToString & vbCrLf & ex.Message & vbCrLf & vbCrLf & ex.StackTrace & Chr(13) & sErrDescription & vbCrLf & vbCrLf & "Press Control + C to copy this error report", MsgBoxStyle.Exclamation + MsgBoxStyle.OkOnly, "Business Management System - Unexepected Error Ref: " & sAuditID)
End If
Finally
' CleanUp
End Try
End Sub
I have spent 2 days now trying to figure out the cause and fix for this problem. There were posts that talked about the image being disposed and not being able to retrieve the image reference [ http://blog.lavablast.com/post/2007/11/29/The-Mysterious-Parameter-Is-Not-Valid-Exception.aspx ] , cloning the image before disposing etc.
I have given disposing and cloning a go, but the error still stands. Been trying couple of other things, but still unsuccessful.
Any suggestions to what is wrong?
EDIT 1
Before closing the form, I clear all the treenodes and then use Me.Close()
Private Sub tsbClose_Click(sender As Object, e As EventArgs) Handles tsbClose.Click
atRootFolder.Nodes.Clear()
atAllDirectories.Nodes.Clear()
atScannedFiles.Nodes.Clear()
atFiles.Nodes.Clear()
atInbox.Nodes.Clear()
atSent.Nodes.Clear()
Me.Close()
End Sub
EDIT 2
My treeviews have hundreds of nodes, child nodes etc. Please see the image of my File Management form ( this is the first time it was loaded, no errors) I had to hide the text due to client confidentiality, but I hope it makes sense. Each image is a node.
imgur.com/QQ2FzFV

Answer 1

I had tried to use GC.Collect to see if it works, and surprising it did. Sadly it worked on one machine and didn't in another. Therefore, instead of calling images directly from my resources, I have stored all required images in an image list which I have attached to my treeviews. It's working like a charm.