HTTPS call fails with "SunCertPathBuilderException: unable to find valid certification path to requested target" or "General SSLEngine problem"

You have developed a Mule application that is calling an HTTPS endpoint and it fails with these errors:

[myapp].http.requester.HTTPS_config.worker(2), fatal error: 46: General SSLEngine problem

Root Exception stack trace:
sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
	at sun.security.provider.certpath.SunCertPathBuilder.build(SunCertPathBuilder.java:146)
	at sun.security.provider.certpath.SunCertPathBuilder.engineBuild(SunCertPathBuilder.java:131)
	at java.security.cert.CertPathBuilder.build(CertPathBuilder.java:280)
	at sun.security.validator.PKIXValidator.doBuild(PKIXValidator.java:382)
	at sun.security.validator.PKIXValidator.engineValidate(PKIXValidator.java:292)
	at sun.security.validator.Validator.validate(Validator.java:260)
	at sun.security.ssl.X509TrustManagerImpl.validate(X509TrustManagerImpl.java:324)
	at sun.security.ssl.X509TrustManagerImpl.checkTrusted(X509TrustManagerImpl.java:281)
	at sun.security.ssl.X509TrustManagerImpl.checkServerTrusted(X509TrustManagerImpl.java:136)
	at sun.security.ssl.ClientHandshaker.serverCertificate(ClientHandshaker.java:1496)
	at sun.security.ssl.ClientHandshaker.processMessage(ClientHandshaker.java:216)
	at sun.security.ssl.Handshaker.processLoop(Handshaker.java:979)
	at sun.security.ssl.Handshaker$1.run(Handshaker.java:919)

CAUSE

That error typically means that the certificate offered by the endpoint is not considered valid to your JDK's default trust store, which may change across different versions of Java.