Hello
When you downloaded WebDisk, did you uncheck the SSL/encrypted connection option? This option is checked by default, but when you try to connect WebDisk looks for a SSL certificate that isn't there. If it was checked (or if you're not sure), try downloading the WebDisk desktop link again with the option unchecked and see if that works.
If it does not, please let us know by submitting a ticket via
http://hostpapasupport.com so we can troubleshoot from our end.
Thank you