As seen eg. on https://www.ssllabs.com/ssltest/analyze.html?d=opencitations.net - as of today opencitations.net provides an incomplete certificate chain. This will result in connection errors from non-browser clients (think API clients, monitoring tools, or try eg. wget https://opencitations.net) and I suppose also some older browsers that do not implement downloading of intermediate certificates.
mpol
commented
2 years ago
As seen eg. on https://www.ssllabs.com/ssltest/analyze.html?d=opencitations.net - as of today opencitations.net provides an incomplete certificate chain. This will result in connection errors from non-browser clients (think API clients, monitoring tools, or try eg.
wget https://opencitations.net) and I suppose also some older browsers that do not implement downloading of intermediate certificates.