SaveAs - user pushing cancel corrupts the file
 

I have a spreadsheet that has a lot of pivot tables, (~10 M). Early versions
of it run fine, but if I Cancel the SaveAs dialog box, the file becomes
corrupted.
After cancelling Save As, Excel crashes everytime I try to update a pivot
table.
I have recreated the file twice. It always works until I push Cancel

Is there something I'm supposed to be doing that I'm not?


savemsg = MsgBox("Please provide a new name for the Summary Mail file.
Please do not push Cancel", vbInformation, SaveAs)

fname = Application.GetSaveAsFilename

If fname < False Then
ActiveWorkbook.SaveAs Filename:=fname
End If

Thanks