The fix for JDK-8040059 has changed the default security policy for jar files in lib/ext in JDK 9 to not grant all permissions by default.
In order for the JavaFX runtime to continue to run when a security manager is present, we will need to add an entry to the java.policy file in the JRE at build time.
JavaFX will provide a new javafx-java.policy file in the artifacts that the FX build delivers into the JDK install build. This file should be concatenated to the lib/security/java.policy file in the JRE (see JDK-8023279 for a similar thing that was done to append entries to lib/ext/meta-index).