Hi William, thanks for your response. The file name does not include any special characters like parentheses or apostrophes and contains only letters, no numbers. It is a multi-page layout (newsletter) originally created in Adobe Illustrator, and uses Illustrator's file compression settings when saving as a PDF. I have done this many, many times before (file names are the same every time; the only thing that changes is the name of the month). Every once in awhile it just gives me an error message and refuses to upload.   My method is to go to "Start Creating", click "Emails", and then upload my PDF - I've tried dragging and dropping and also manually selecting the file from my computer.  ... View more