This error can occur when you try and upload a file that is
- Not a PDF file, or a PDF too big in size. The recommended file size is 15 MB, and the max size is 20 MB. Read more here: Which files can I upload to Penneo? (file size limits).
- The PDF you are trying to upload is password-protected. Remove the password and try again.
- The PDF file has been corrupted.
In most cases, this issue can be resolved by printing the PDF - thereby creating a new PDF.
To print a PDF, open the PDF, click on the print option and change the printer to Save as PDF. Then, print the file and save it. Try uploading the new PDF to Penneo.
We recommend using Penneo's PDF printer; read about it here: How to install and use the Penneo Printer.
If the problem persists, please do not hesitate to contact our Customer Support team.