I have free Comodo SSL certifficate from Cludflare and i cant access my website via https via Android 2.3.6 and also on Windows XP internet explorer. These are old apps, but still i think it is quite a issue. ssllabs.com/ssltest says following errors when i test my domain: Android 2.3.7 No SNI 2 Server sent fatal alert: internal_error IE 6 / XP No FS 1 No SNI 2 Server sent fatal alert: handshake_failure IE 8 / XP No FS 1 No SNI 2 Server sent fatal alert: internal_error SNI - Browser does not support Server Name Indication FS - Browser effectively does not support Forward Secrecy Please what do you suggest? I do not wish to purchase SSL. I see Lets Encrypt free SSL has A+ rating on this page: https://www.ssllabs.com/ssltest/analyze.html?d=minehub.de Free WoSign certifficate shows some mismatch error, but shows the https page. Is my only option to switch to other certificate authority? Which one will allow me to browser on IE6, IE8 and old Android as mentioned?
Older browsers are not going to support the newer features like SNI. Other than browser sniffing and redirecting visitors with browsers that support those features to https, I don't know what you can do. I read the CloudFlare documentation regarding this issue and their only suggestion was to upgrade. So it doesn't look like you have much choice.
This has to do with non-supported modern SSL-versions in older apps. Either, as suggested, you'll have to put in some sort of redirect for these older browsers, or just inform them that they're part of the problem, and tell them to upgrade. Which they should, regardless. It's really unsafe surfing with those old setups, as there are plenty of unpatched security holes around, and they're just begging to be pwned by some scriptkiddie with too much free time.
I think you are wrong. I mentioned already that minehub.de is accessible even via old apps/OS thanks to LetsEncrypt free SSL, but Cloudflare not which is bad i think. Seems i canot use free Cloudflare and my own SSL (letsencrypt) at same time, soo annoyed.