Recently received email from LetsEncrypt:
Your Let’s Encrypt client used ACME TLS-SNI-01 domain validation to issue
a certificate in the past 60 days.
TLS-SNI-01 validation is reaching end-of-life. It will stop working
temporarily on February 13th, 2019, and permanently on March 13th, 2019.
Any certificates issued before then will continue to work for 90 days
after their issuance date.
You need to update your ACME client to use an alternative validation
method (HTTP-01, DNS-01 or TLS-ALPN-01) before this date or your
certificate renewals will break and existing certificates will start to
If you’re a Certbot user, you can find more information here:
What can you advise to do to keep https working?
Thank’s a lot!