I've had 5 clients this week tell me that they cannot open the .pdf's I have created in Corel Draw. I have tried the Save As function, the Export Function, and the Publish to PDF function, and there doesn't seem to be a difference for the clients.
Other posts have suggested using a different program to open the files, but I have not control over what a client uses to open them.
I am running Corel Draw 2017 ver. 19.1.0.419, on Windows 10 Pro ver. 1709
Acrobat reader would be the standard test as it's free and Adobe. Can you post a PDF file or a link to download a PDF file that fails for your client? Sometimes using fonts that are not licensed for embedding causes issues.
I can't post the .pdf's, since they're confidential. My apologies. But I can have a look at the fonts being embedded.