ssl certificate not trusted (this root certificate is not trusted)

Hello,
I have created a ssl certificate for server own with guide.
(https://help.directadmin.com/item.php?id=15)

After all, when I tried https link to login there is an error! "this root certificate is not trusted"
I have fulfilled all steps and details when I create cert.
I want to all directadmin user use on ssl with :2222

Best regards.

I have changed certificate with Let's Encrypt automated free SSL certificate installs
https://help.directadmin.com/item.php?id=15
I had an error again:

Waiting for domain verification...
rm: cannot remove `/var/www/html/.well-known/acme-challenge/': Is a directory
Challenge is . Details: . Exiting...

Than fixed it: http://forum.directadmin.com/showthread.php?t=53238

Works fine...

Best regards.

Modern browsers don't like self-signed certificates. As long as you trust the site it is perfectly fine to tell the browser to connect anyway. If you would like to not be warned, then you need to either buy a certificate or use something like LetsEncrypt which should be trusted by most browsers.