I purchased and uploaded a SSL certificate for my domain, but "This site is not trusted" error is still show in browser. Google Chrome browser displays the following information about the site page:
These page includes another resource which are not secure
This happens because the web page you are requesting contains references to other resources which are not being retrieved over SSL/TLS. For example, the page may contain a link to a static image like so:
In this case, the browser is warning you that while the page you are requesting is claiming to be secure, it really is not it.
It is needed to rewrite site code to fix the issue. To find unencrypted content use browser console, for example hit
CTRL+Shift+J and you will see text like:
"The page at https://example.com/index.php contains insecure content from http://example.com/picture.jpg"