What about the issue that I've opened the post for. Did you manage to find out the problem?
Thanks!

I have another question: is there a way that in the local wiev to see a tree folder structure? Thanks.

I think the best way to secure the ftp server when using jdiskexplorer is to include the url and the login credentials in the i18n.properties file and then restrict the acces to .properties files with htaccess. I figured out that if i enabel the connect button in the interface and click on it after ...

The problem sounds like this: With my login credentials as parameters in applet_ftp_explorer.js the applet connects to the ftp server and displays the remote files at first load. If the login credentials are in the i18n.properties file the applet doesn't connect anymore when the page is first loaded...