When trying to access Karrot by Google Chrome browser I get the following screen:
It has been reported by multiple users and on different browsers.
@tiltec @djahnie Could you please look into it as soon as possible? It’s difficult to manage our activities without Karrot 
I fixed it just now, thanks for reporting!
We have an automated certificate renewal process using https://letsencrypt.org/ and GitHub - zenhack/simp_le: Simple Let's Encrypt client, but it seems to have failed without warning this time. I’ll try to find out why there was no warning and why the process failed. I might also switch to a different “Let’s encrypt” client like GitHub - certbot/certbot: Certbot is EFF's tool to obtain certs from Let's Encrypt and (optionally) auto-enable HTTPS on your server. It can also act as a client for any other CA that uses the ACME protocol..
Thanks for such a quick action. Karrot is up and running now 
