output of certbot -version or certbot-auto -version if you're using Certbot): I'm using a control panel to manage my site (no, or provide the name and version of the control panel): I can login to a root shell on my machine (yes or no, or I don't know): The operating system my web server runs on is (include version): crt.sh | ), so withholding your domain name here does not increase secrecy, but only makes it harder for us to provide help. Domain names for issued certificates are all made public in Certificate Transparency logs (e.g. Note: you must provide your domain name to get help. Please fill out the fields below so we can help you better. Please answer all the questions to the best of your knowledge: In any case, it's required for getting the best help possible. Maybe you didn't get it in the first place, maybe you've deleted it. However, it seems the questionnaire you should have seen when opening a thread in the #Help section is gone. The davfs package should be able to use the systems root certificate store to verify the certificate chain.