while trying to validate my TLS demonstration server https://tls.openmirage.org I discovered that validator.w3.org cannot connect to it.

tls.openmirage.org uses a clean-slate TLS implementation (from https://github.com/mirleft/ocaml-tls), which only supports TLS-1.0, TLS-1.1, and TLS-1.2. No SSL 3.

Unfortunately I do not know enough of Perl to tweak the validator to fix the issue, but someone with a better understanding of the code base might be able to do so.