Search plugin don't work

HTTP ERROR: 500

org.jivesoftware.openfire.archive.ConversationManager.componentUnregistered(Lorg/xmpp/packet/JID;)V

RequestURI=/plugin-admin.jsp

Caused by:

java.lang.AbstractMethodError: org.jivesoftware.openfire.archive.ConversationManager.componentUnregistered(Lorg/xmpp/packet/JID;)V
     at org.jivesoftware.openfire.component.InternalComponentManager.notifyComponentUnregistered(InternalComponentManager.java:246)
     at org.jivesoftware.openfire.component.InternalComponentManager.removeComponent(InternalComponentManager.java:232)
     at org.jivesoftware.openfire.component.InternalComponentManager.removeComponent(InternalComponentManager.java:192)
     at org.jivesoftware.openfire.plugin.SearchPlugin.destroyPlugin(SearchPlugin.java:173)
     at org.jivesoftware.openfire.container.PluginManager.unloadPlugin(PluginManager.java:584)
     at org.jivesoftware.openfire.admin.plugin_002dadmin_jsp._jspService(plugin_002dadmin_jsp.java:140)
     at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:97)
     at javax.servlet.http.HttpServlet.service(HttpServlet.java:820)
     at org.mortbay.jetty.servlet.ServletHolder.handle(ServletHolder.java:487)
     at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1093)
     at com.opensymphony.module.sitemesh.filter.PageFilter.parsePage(PageFilter.java:118)
     at com.opensymphony.module.sitemesh.filter.PageFilter.doFilter(PageFilter.java:52)
     at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1084)
     at org.jivesoftware.util.LocaleFilter.doFilter(LocaleFilter.java:66)
     at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1084)
     at org.jivesoftware.util.SetCharacterEncodingFilter.doFilter(SetCharacterEncodingFilter.java:42)
     at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1084)
     at org.jivesoftware.admin.PluginFilter.doFilter(PluginFilter.java:70)
     at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1084)
     at org.jivesoftware.admin.AuthCheckFilter.doFilter(AuthCheckFilter.java:99)
     at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1084)
     at org.mortbay.jetty.servlet.ServletHandler.handle(ServletHandler.java:360)
     at org.mortbay.jetty.security.SecurityHandler.handle(SecurityHandler.java:216)
     at org.mortbay.jetty.servlet.SessionHandler.handle(SessionHandler.java:181)
     at org.mortbay.jetty.handler.ContextHandler.handle(ContextHandler.java:726)
     at org.mortbay.jetty.webapp.WebAppContext.handle(WebAppContext.java:405)
     at org.mortbay.jetty.handler.ContextHandlerCollection.handle(ContextHandlerCollection.java:206)
     at org.mortbay.jetty.handler.HandlerCollection.handle(HandlerCollection.java:114)
     at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152)
     at org.mortbay.jetty.Server.handle(Server.java:324)
     at org.mortbay.jetty.HttpConnection.handleRequest(HttpConnection.java:505)
     at org.mortbay.jetty.HttpConnection$RequestHandler.headerComplete(HttpConnection.java:829)
     at org.mortbay.jetty.HttpParser.parseNext(HttpParser.java:514)
     at org.mortbay.jetty.HttpParser.parseAvailable(HttpParser.java:211)
     at org.mortbay.jetty.HttpConnection.handle(HttpConnection.java:380)
     at org.mortbay.io.nio.SelectChannelEndPoint.run(SelectChannelEndPoint.java:395)
     at org.mortbay.thread.QueuedThreadPool$PoolThread.run(QueuedThreadPool.java:488)

this is what he say when i em trying to reload plugin from admin console.
when installing plugin in say's "search plugin installed succesfuly", but it don't appeared in console, and Spark says that "no search servers found".

openfire 3.6.0

error appears after upgrading openfire from 3.5.2

dunno whats happening. delete the search plugin from plugins derictory, installed once again the latest search plugin and second rebbot of server solved the problem …

last massege describes the solving of problem