There are 3 methods to test the incomplete certificate chain: 1) https://www.ssllabs.com/ssltest/analyze.html?d=example.com The error is: Chain issues Incomplete 2) curl -v -o /dev/null https://example.com The error is: * NSS error -8179 (SEC_ERROR_UNKNOWN_ISSUER) * Peer's Certificate issuer is not recognized. 3) openssl s_client -showcerts -verify 10 -connect example.com:443 The error is: Verify return code: 21 (unable … Continue reading Incomplete certificate chain →