Link to Monitoring Service page missing

Hello
about 2 weeks that the shortcut to the Monitoring service page gone of the Openfire server page. If I access the link “http: // meuervidor: 9090 / plugins / monitoring / archive-search.jsp” I can see the conversation history but if I do a search by key-word happens the following error.

It is already a plugin, updates JAVA, I installed an older version of JAVA and nothing worked.
A versão do Openfire é: 4.2.3 e do Monitoring Service é 1.6.2

O erro que aparece quando faço uma busca por palavra é:
Exceção:
java.lang.NullPointerException

at org.apache.lucene.index.SegmentInfos$FindSegmentsFile.run(SegmentInfos.java:564)

at org.apache.lucene.index.DirectoryReader.open(DirectoryReader.java:73)

at org.apache.lucene.index.IndexReader.open(IndexReader.java:476)

at org.apache.lucene.index.IndexReader.open(IndexReader.java:300)

at org.apache.lucene.search.IndexSearcher.(IndexSearcher.java:87)

at org.jivesoftware.openfire.archive.ArchiveIndexer.getSearcher(ArchiveIndexer.java:578)

at org.jivesoftware.openfire.archive.ArchiveSearcher.luceneSearch(ArchiveSearcher.java:116)

at org.jivesoftware.openfire.archive.ArchiveSearcher.search(ArchiveSearcher.java:101)

at org.jivesoftware.openfire.plugin.monitoring.archive_002dsearch_jsp._jspService(archive_002dsearch_jsp.java:239)

at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)

at javax.servlet.http.HttpServlet.service(HttpServlet.java:790)

at org.jivesoftware.openfire.container.PluginServlet.handleJSP(PluginServlet.java:382)

at org.jivesoftware.openfire.container.PluginServlet.service(PluginServlet.java:97)