I'm not install this plugin. In Windows, logs must be stored in: C:\Program Files (x86)\Openfire\logs\stdout.log
Give me anser of server for this command:
<iq type="get" id="sid_134">
<list xmlns="urn:xmpp:archive" with="user2@host.tld">
<set xmlns="http://jabber.org/protocol/rsm">
<max>10000</max>
<before/>
</set>
</list>
</iq>