JDK9 provides -XaddExports launch option to workaround potential migration problems to modularized JDK.
When modularized JDK forks new process all -XaddExports values are translated into
-Djdk.launcher.addexports.%d=%s JVM options.
But method org.jboss.as.host.controller.Main.getHostSystemProperties()
has problems with its values.

The format of -XaddExports (and thus for -Djdk.launcher.addexports.%d=%s too) is:

-XaddExports:<source-module>/<package>=<target-module>(,<target-module>)*

See http://openjdk.java.net/jeps/261 for more information.