I get today a mail with the following information:
Action is required to prevent your Let’s Encrypt certificate renewals from breaking.
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 and will stop working on February 13th, 2019.
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 expire.
If you need help updating your ACME client, please open a new topic in the Help category of the Let’s Encrypt community forum:
What a question: Nothing is clear, I have absolut no idea what I have to do.
Its first time I hear about ACME and TLS-SNI-01
I’m using a Synology workstation with DSM 6.2.1 and use a Let’s Encrypt certificate which was created in an automatic way, so I have no idea, which protocol the certificate use and where I can change the settings. I have looked in my NAS and her I saw, the the Let’s Encrypt Authority X3 certificate is valied up to 15. March 2019.
Please tell me what I have to do and how I can do it?
Thank you very much for supporting me