In most cases error messages that you get when you publish Helpinator content to Wordpress are informative and easy to fix. Except two cases: "Access denied" and "Moved permanently".
1. Access denied
Nowdays there are many shared hosting providers that block Wordpress XML-RPC access by default. This is why you get this error message. There are two possible solutions for this problem - contact your hosting provider and ask them to allow XML-RPC or just rename xmlrpc.php file that is in the root folder of your WordPress installation to, say, xmlrpc123.php.
Helpinator allows to specify "Endpoint" in the "Publish to Wordpress" settings dialog. Essentially it is the name of the xmlrpc.php file. So, in our case you can set it to xmlrpc123.php.
Setting "Endpoint" to the renamed xmlrpc123.php file
2. Moved permanently
Typically this problem arises from Wordpress caching plugins, especially WP Super Cache and W3 Total Cache. The only way to fix it is to temporarily disable caching plugins before you publish content and then enable them back.