Does the error only occur in webtop? It seems you have a bad certificate so I am afraid the whole webserver is affected.
Did you upload a certificate?
Please post the output of the following command to check the actual config:
config show pki
Did you change
/etc/httpd/conf.d/ssl.conf, if yes please post the output of:
grep SSLCert /etc/httpd/conf.d/ssl.conf
I also get this error when I try to open an http page with https. Do you do some port forwarding or reverse proxying?