update and install plugins is not working…
it seems these URLs are down:
Unable to connect to the jMonkeyEngine SDK Stable because of http://updates.jmonkeyengine.org/stable/3.1/plugins/updates.xml
Unable to connect to the NBAndroid Updates because of Server returned HTTP response code: 403 for URL: http://nbandroid.org/release81/updates/updates.xml
Unable to connect to the jMonkeyEngine SDK User Contributions because of http://updates.jmonkeyengine.org/contrib/3.1/updates.xml
Unable to connect to the jMonkeyEngine SDK Nightly (Breaks!) because of http://updates.jmonkeyengine.org/nightly/3.1/plugins/updates.xml