Answered by : elated-emu-n0hr7d100z26

 Add the line below before </policymap> in the /etc/ImageMagick-7/policy.xml <policy domain="coder" rights="read | write" pattern="PDF" />

Source : https://stackoverflow.com/questions/52998331/imagemagick-security-policy-pdf-blocking-conversion | Last Update : Mon, 29 Jun 20