w3c-markup-validator-1.3-6.fc20 lacks dependencies on several Perl modules, including those provided by these RPMs: perl-Encode-HanExtra perl-HTML-Encoding perl-JSON perl-Net-IP perl-SGML-Parser-OpenSP Manually installing those RPMs gets around the problem. Now that bug 1051598 has been fixed this problem should be solved simply by rebuilding the w3c-markup-validator package for both rawhide and F20. Older releases already have the required dependencies.
w3c-markup-validator-1.3-7.fc20 has been submitted as an update for Fedora 20. https://admin.fedoraproject.org/updates/w3c-markup-validator-1.3-7.fc20
Package w3c-markup-validator-1.3-7.fc20: * should fix your issue, * was pushed to the Fedora 20 testing repository, * should be available at your local mirror within two days. Update it with: # su -c 'yum update --enablerepo=updates-testing w3c-markup-validator-1.3-7.fc20' as soon as you are able to. Please go to the following url: https://admin.fedoraproject.org/updates/FEDORA-2014-1522/w3c-markup-validator-1.3-7.fc20 then log in and leave karma (feedback).
w3c-markup-validator-1.3-7.fc20 has been pushed to the Fedora 20 stable repository. If problems still persist, please make note of it in this bug report.