I wanted to mount my webdav share which is using certificate backed by CA "Let's Encrypt". Unfortunately pantheon-files declare that CA is not trusted (not found). This CA is perfectly workable and fine in firefox. Do they use different cert store, pantheon-files and firefox?
Get the CA which is missing. In my case:go to lets encrypt web site (or any other missing CA cert site). Copy the CA in PEM format (the format that has ----BEGIN CERTIFICATE---- in it) into
/usr/local/share/ca-certificates and name it with a .crt file extension.
You can verify if this worked by looking for the certificate that you just added in