Feature "http://xml.org/sax/features/external-parameter-entities" is not supported

On one of my test systems, I received the following message:

[junit] WARN class
com.sun.org.apache.xerces.internal.jaxp.DocumentBuilderFactoryImpl does not
support updating feature
http://xml.org/sax/features/external-general-entitiesjavax.xml.parsers.ParserConfigurationException:
jaxp_feature_not_supported: Feature "
http://xml.org/sax/features/external-general-entities" is not supported.

when trying to disable the processing of external general entities. Does
that mean disabling the processing of external general entities is not
supported, or the processing itself is not supported?

Unfortunately I can't test it currently, as the configuration of the build
on that system seems to have been changed since then.

Thanks

Matt