First issue more than likely you did not either enter the VB
license number or set your cookies to match that of VB
. Most usual issue is people do not set the cookie prefix to bb which is the default vb3 cookie prefix when they install the app.
Second Issue in Admin Global Options check your uploads and data server paths as they are set to . and not /var/www/classifieds/data and /var/www/html/classifieds/uploads