The maximum file size allowed is 4Mb. You will need to reduce the PDF file size or use a Compressed (Zipped) Folder.
To Zip a File:
- Locate the file or folder that you want to zip.
- Press and hold (or right-click) the file or folder, select (or point to) Send to, and then select Compressed (zipped) folder.
- A new zipped folder with the same name is created in the same location.
To reduce a file size:
- Open the PDF
- Click File >Save as Other
- Select Reduce Size PDF
Compress PDF Online: https://smallpdf.com/compress-pdf