Drupal D7 Ellfinder elfinder-7.x-2.x-dev error "Invalid backend response.Data is empty"

I have a very strange situation with Elfinder. I developed a Drupal D7 website on a development (Ubunt 12.04) server. Everything, including CKEditor and Elfinder works perfect. I migrated the website (file system and mysql database) to a Zpanel Linux Ubuntu 12.4 server and I didn't get elfinder working any more.