There's an oddity with i18n in the admin panel: when the to-be-translated text contains placeholders as well as apostrophes, the placeholders are not filled out. In version 4.0.0 it is visible on /connection-settings-socket-c2s.jsp:
Use the forms below to configure how XMPP clients connect to the XMPP domain thats provided by this server. You can also {0}view the client sessions{1} that are currently connected to this server.
instead of the expected:
Use the forms below to configure how XMPP clients connect to the XMPP domain that's provided by this server. You can also view the client sessions that are currently connected to this server.
Suggested fix: use html-encoded characters instead of apostrophes. PR: https://github.com/igniterealtime/Openfire/pull/521
PR merged into trunk and cherry-picked into 4.0