GeoServer 2.9 may not start if native JAI is installed in the JDK/JRE

Having JAI both in the webapp and in the JRE/JDK prevents startup with Jetty 9.
A simple workaround is to remove JAI from GeoServer WEB-INF/lib as suggested in the install guide (the difference being that right now the step is no more optional):

http://docs.geoserver.org/latest/en/user/production/java.html#geoserver-cleanup

So, two options:

• Update the docs

• See if changing the classloading options in Jetty makes it start anyways