Java 9 Support: Starting with this version we are providing Java 9 support in an early access program (EAP). Switching existing FirstSpirit installations to use Java 9 requires changes to the configuration. Due to extended security checks introduced in Java 9 you will likely experience a slower than usual behaviour of the system, especially during start-up and when using dynamically loaded functionality for the first time. Please also be aware that third-party software used in FirstSpirit may not yet be fully prepared for Java 9.
Detailed information on configuration changes required and Java 9 support in general can be found in chapter 3 "Oracle Java" of the release notes attached to this post.