It doesnt support browsers in Windows XP and it is the only annoying thing which forced me to rollback letsencrypt. I know it is 2016 but complaining clients is not what you want anyway.
I still have no idea if they are able to fix this in future.
I still have no idea if they are able to fix this in future.
[1] https://github.com/letsencrypt/letsencrypt/issues/1660
[2] https://community.letsencrypt.org/t/help-needed-windows-xp-s...