Hello. if you have a minute, I've checked the Internet Settings and TLS 1.0, TLS 1.1, TLS 1.2 are all checked and I've seemingly tried everything else on the internet regarding this error (clearing cache, etc). Anyways, in summary...
- was provided self-signed cert/private key in pfx file by the organization
- used openssl to convert pfx to pem (NOTE: when first attempting, received an error that openssl does not support RC2, so used the -legacy parameter to allow openssl to convert to pem)
- Converted pem to txt file and had to fix the order of certificate nodes in the txt file to server-intermediate-root.
- Imported the txt file into Domino keyring file, verified using their tool and it said everything cool.
- Pointed Domino to that keyring.kyr file, restarted server.
- Get "Can't connect securely to this page. This might be because the site uses outdated or unsafe TLS settings".
I tried all the internet options and client stuff. Oh, the client is running IE mode in Edge.