Unknown: Cannot use output buffering in output buffering display handlers in Unk

I would need more information to figure this out. It’s probably some specific issue with that plugin or the post title. There is an option on both the tool and the settings pages to include shortcode proecessing from other plugins, but of course, it doesn’t always work, because the PDF generation is running in a slightly different context than when a regular page is processed and displayed to the user.