Pega Infinity 8 versions are supported on Java 8. We are currently testing a Java 11and plan to support it in a future release. Java 9 is out of support as of March 2018, and Java 10 is out of support as of September 2018, so those versions are not being certified with Pega Infinity.
Oracle stopped provisioning & supporting entire Java 6 versions and Java 7 itself is limited. Therefore, Pega is neither supported nor tested in Java 6 legacy versions.
Have just a query, is compatibility of JAVA version a probable reason for error stated below -
SEVERE: Error generating RMI code: RMIC command failed on project: prbeans with message:
error: Invalid class file format in /opt/websphere-profiles/wstemp/appmgmt/mbean/AppManagement/EarContent/APP-INF/lib/prbootstrap-api.jar(com/pega/pegarules/internal/etier/interfaces/Engine.class). The major.minor version '52.0' is too recent for this tool to understand."