The HTTP status code HTTP 403 – Forbidden simply means the request for a given resource (say a page or file) is not allowed even through authentication. This can be caused for a few reasons with web servers but the know inssue is listed below.
Using Auto-downloads With Mixed HTTP/HTTPS URLs
If you or your customers are receiving this error when trying to access your auto-download files (via the link sent in the confirmation email) you may be using a mixture of http/https prefixes on your URLs. In order to prevent this please use http:// for all auto-download URLs when you set them up in your Cart32 Administration.