SaveAs PDF problem

[JohnnyBravo]

I'm running Word 2016 version and I'm having an issue with a VBA routine I found on line. All i'm trying to do is to save as pdf. The routine works fine if the word doc is brand new and it hasn't been saving before. The routine checks to see if the document has been saved before, let's call it "Sales Proposal 1" and if it has, it prompts the user with 3 choices: "Sales 1 proposal" is already on your PC, do you wish to overwrite it? YES, NO, Cancel.

The error message is generated whenever I click on 'NO' it gives the following message:

invalid procedure call or argument
It's seems to be having an issue with the 'SaveAs2' part towards the bottom of the script below in the functions section. (The bold & underline is my emphasis only so you can spot it quicker).

Any assistance would be greatly appreciated. Thanks.

Here is the VBA routine:
=========================================================================== ================================

Sub Word_ExportPDF()
'PURPOSE: Generate A PDF Document From Current Word Document
'NOTES: PDF Will Be Saved To Same Folder As Word Document File
'SOURCE: www.TheSpreadsheetGuru.com/the-code-vault

Dim CurrentFolder As String
Dim FileName As String
Dim myPath As String
Dim UniqueName As Boolean

UniqueName = False

'Store Information About Word File
  myPath = ActiveDocument.FullName
  CurrentFolder = ActiveDocument.Path & ""
  FileName = Mid(myPath, InStrRev(myPath, "") + 1, _
   InStrRev(myPath, ".") - InStrRev(myPath, "") - 1)

'Does File Already Exist?
  Do While UniqueName = False
    DirFile = CurrentFolder & FileName & ".pdf"
    If Len(Dir(DirFile)) <> 0 Then
      UserAnswer = MsgBox("Filename Already Exists! Click " & _
       "[Yes] to override. Click [No] to Rename.", vbYesNoCancel)
      
      If UserAnswer = vbYes Then
        UniqueName = True
      ElseIf UserAnswer = vbNo Then
        Do
          'Retrieve New File Name
            FileName = InputBox("Provide New File Name " & _
             "(will ask again if you provide an invalid file name)", _
             "Enter File Name", FileName)
          
          'Exit if User Wants To
            If FileName = "False" Or FileName = "" Then Exit Sub
        Loop While ValidFileName(FileName) = False
      Else
        Exit Sub 'Cancel
      End If
    Else
      UniqueName = True
    End If
  Loop
  
'Save As PDF Document
  On Error GoTo ProblemSaving
    ActiveDocument.ExportAsFixedFormat _
     OutputFileName:=CurrentFolder & FileName & ".pdf", _
     ExportFormat:=wdExportFormatPDF
  On Error GoTo 0

'Confirm Save To User
  With ActiveDocument
    FolderName = Mid(.Path, InStrRev(.Path, "") + 1, Len(.Path) - InStrRev(.Path, ""))
  End With
  
  MsgBox "PDF has now been saved in the Folder: " & FolderName

Exit Sub

'Error Handlers
ProblemSaving:
  MsgBox "There was a problem saving your PDF. This is most commonly caused" & _
   " by the original PDF file already being open."
  Exit Sub

End Sub


Function ValidFileName(FileName As String) As Boolean
'PURPOSE: Determine If A Given Word Document File Name Is Valid
'SOURCE: www.TheSpreadsheetGuru.com/the-code-vault

Dim TempPath As String
Dim doc As Document

'Determine Folder Where Temporary Files Are Stored
  TempPath = Environ("TEMP")

'Create a Temporary XLS file (XLS in case there are macros)
  On Error GoTo InvalidFileName
    Set doc = ActiveDocument.SaveAs2(ActiveDocument.TempPath & _
     "" & FileName & ".doc", wdFormatDocument)
  On Error Resume Next

'Delete Temp File
  Kill doc.FullName

'File Name is Valid
  ValidFileName = True

Exit Function

'ERROR HANDLERS
InvalidFileName:
'File Name is Invalid
  ValidFileName = False

End Function