convert-im6.q16: not authorized `moment_rate.eps' @ error/constitute.c/ReadImage/412.

convert

is a powerful command line tool to convert graphics. Allegedly, that provides security risks, especially where it is used in conjunction with a web server. In recent versions of Ubuntu, a policy file is implemented, where certain uses of

convert

are restricted. Apparently, that file by default prohibits "converting" multiple graphic files into one PDF file.

The policy file is

/etc/ImageMagick-6/policy.xml

. You may edit that file as root user to change the policies.

Eliminating all usage restrictions

For desktop users not running a webserver, simply eliminating these restrictions might be good enough. To that aim, one may delete the file, but it is better practice to "move the file out" by renaming it. With this command, you are renaming the file. As a result, all policies are lifted, but you still can revert if needed:

sudo mv /etc/ImageMagick-6/policy.xml /etc/ImageMagick-6/policy.xmlout

To revert to the original situation, just rename back to the original name:

sudo mv /etc/ImageMagick-6/policy.xmlout /etc/ImageMagick-6/policy.xml

Eliminating only the restriction to combine into PDF

For your specific case, gene_wood in a comment pointed to the posibility to selectively relax the policy for working with PDF files by commenting out one line:

<policy domain="coder" rights="none" pattern="PDF" />

Edit the file, and place comment marks around this line to disable this rule:

<!-- <policy domain="coder" rights="none" pattern="PDF" /> -->

If you do not want to eliminate all security policies, this is the way to go.

Disclaimer: you have been warned that removing this policy file removes certain security policies.