When sub runs for the second time, the program freezes - vb.net

Question

I've been doing a skin stealer, but for some reason, when I re-click button 3, it just freezes. Note that I've added the MsgBoxes to know where it freezes (As far as I know, it freezes at AssembleSkin()). I have no idea why it would do that, so if you have an idea why, go ahead and post a suggestion! Thanks
Private Sub Button3_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button3.Click
If TextBox1.Text = "" Then
Else
MsgBox("1")
Dim request = DirectCast(WebRequest.Create _
("http://www.minecraft.net/skin/" + TextBox1.Text + ".png"), WebRequest)
MsgBox("2")
Try
Dim response As WebResponse = DirectCast(request.GetResponse(), WebResponse)
MsgBox("3")
AssembleSkin(FindImage(TextBox1.Text), PictureBox1, PictureBox2, PictureBox5, PictureBox6, PictureBox3, PictureBox4)
MsgBox("4")
Dim Skin As Image = FindImage(TextBox1.Text)
MsgBox("5")
PictureBox7.Image = SizeImage(Skin, 300, 150)
Catch ex As WebException
Dim response As WebResponse = DirectCast(ex.Response, WebResponse)
MsgBox("Skin does not exist", MsgBoxStyle.OkOnly, "Mynecraft V2")
End Try
End If
End Sub
Private Function FindImage(ByVal Username As String) As Image
Dim tClient As WebClient = New WebClient
Dim tImage As Bitmap = Bitmap.FromStream(New MemoryStream(tClient.DownloadData("http://www.minecraft.net/skin/" + Username + ".png")))
Return tImage
End Function
Public Function GetPicturePart(ByVal SourceImage As Bitmap, ByVal Region As Rectangle) As Bitmap
Dim ImagePart As Bitmap = New Bitmap(Region.Width, Region.Height)
Using G As Graphics = Graphics.FromImage(ImagePart)
Dim TargetRect As Rectangle = New Rectangle(0, 0, Region.Width, Region.Height)
Dim SourceRect As Rectangle = Region
G.DrawImage(SourceImage, TargetRect, SourceRect, GraphicsUnit.Pixel)
End Using
Return ImagePart
End Function
Private Function SizeImage(ByVal img As Bitmap, ByVal width As Integer, ByVal height As Integer) As Bitmap
Dim newBit As New Bitmap(width, height)
Dim g As Graphics = Graphics.FromImage(newBit)
g.InterpolationMode = Drawing2D.InterpolationMode.NearestNeighbor
g.PixelOffsetMode = Drawing2D.PixelOffsetMode.Half
g.DrawImage(img, 0, 0, width, height)
Return newBit
End Function
Private Sub AssembleSkin(ByVal Image As Image, ByVal Head As PictureBox, ByVal Body As PictureBox, ByVal LeftArm As PictureBox, ByVal RightArm As PictureBox, ByVal RightLeg As PictureBox, ByVal LeftLeg As PictureBox)
Head.Image = SizeImage(GetPicturePart(Image, New Rectangle(New Point(8, 8), New Size(8, 8))), 64, 64)
Body.Image = SizeImage(GetPicturePart(Image, New Rectangle(New Point(20, 20), New Size(8, 12))), 64, 96)
LeftArm.Image = SizeImage(GetPicturePart(Image, New Rectangle(New Point(44, 20), New Size(4, 12))), 32, 96)
RightArm.Image = SizeImage(GetPicturePart(Image, New Rectangle(New Point(44, 20), New Size(4, 12))), 32, 96)
LeftLeg.Image = SizeImage(GetPicturePart(Image, New Rectangle(New Point(4, 20), New Size(4, 12))), 32, 96)
RightLeg.Image = SizeImage(GetPicturePart(Image, New Rectangle(New Point(4, 20), New Size(4, 12))), 32, 96)
End Sub

Answer 1

ByVal Image As Image
;o first time i've seen this notation.
also, in your catch statement check the ex.tostring stack trace. (or using system.diagnostics.stacktrace)/
also, what happens when the findimage method returns null, and that is passed to the assembleskin method. that also has a high probability of being the issue.
in any case, check the exception code/trace.