This error comes up due to corrupt installation of smug mug plugin.
So could you please uninstall the smug- mug plugin and then reinstall it from the below link:
Thanks so much for your speedy input!
Unfortunately, the article doesn't exactly explain how to uninstall the plugin.
Do I have to remove the publish service?
Yes,you can do that by removing it from Plug-in Manager and installing it by following the steps mentioned in the above article.