Java 1.8.0_131 disabled MD5 algorithm. As a result, any server that has keystore based on this old algorithm will result in this error sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target More info: https://www.oracle.com/technetwork/java/javase/8u131-relnotes-3565278.html Current Payment Gateway keystore >keytool -list -keystore keystore.bin -v Enter keystore password: Keystore type: ..