If you are seeing in your browser or in your site access log the following two error logs:
"Access denied with code 406"
OR
"Not Acceptable An appropriate representation of the requested resource / could not be found on this server"
That means that your application/site has triggered one of our default application firewall rules (for our shared Linux, and shared Linux reseller servers - modsec / mod_security).
Please, contact our support so that we can assist you with this error.