It says my connection isn't private when i do encrypted mode what happened
RapidSSL is the certificate vendor, and their certificates are not yet fully trusted by at least some versions of Chrome.
(Notice now Chrome isn't on RapidSSL's list [icons at the bottom]):
https://www.rapidssl.com/learn-ssl/ssl-browser-recognition/
So, this doesn't mean your connection isn't encrypted. It is. It doesn't even mean that anyone could decrypt it more easily than a SSL certificate from any other vendor. They can't. It just means that you have to tell Chrome to accept the certificate.
