As new versions of MRules have been released, supported Java versions have evolved. We are making our best to support old JDK versions as long as possible. But new features integration and news versions support sometimes require to remove an old version from supported list.
Current MRules version (2.6.0) is fully compatible and certified with JDK 6, 7 and 8. UI modules based on Vaadin require JDK 8.
JDK 9 and later still show compatibility issued, mainly at the grammar engine level, even if last versions improve them.
The version to come (2.7.0) will bring full compatibility with JDK 9 to 15. 16 and later won’t be included for now.
But, we had to make the difficult decision to remove JDK 6 from our supported versions list. Thus, JDK7 extension will be deprecated and reintegrated directly in core modules.