Hi @kevinbazira
I am unable to do what you have recommended because when I try to edit the post that is when the white page and the error message is triggered. I am able to visit the site and see the PDF Viewer without issues.
On top of that, this is not just for a single post but rather every post that I create hast this problem. As soon as I publish the post if I got back to “all posts” and select to “edit” the newly created post, I get the white page.
I am using the “polylang” language as my site uses two languages. Is it possible this might be affecting how PDF Viewer attempts to locate the pdf file when editing it?