Hello,
Please follow these steps to debug it:
http://www.phpdocx.com/documentation/conversion-plugin/debugging-libreoffice
The most common issue is missing rw access to the .config folder of the HOME user used by the web server (4th item on this same page).
We replied all your emails from contact[@]phpdocx.com , but your server returns an error. We have replied your last email too.
Regards.