The update problem? Usually, it might happens because:
1. You are using quite old version. That old version still has Download URL pointed to old URL (http url), we implemented SSL certificate for our website from the beginning of this year, so URL was changed
2. The Download ID is wrong or it was using for a different website. In this case, generate and use new download id would work
3. Subscription Expired
If you could not update for some reasons, you can access to My Downloads menu item to download latest version and update manually
Tuan
