[xwiki-devs] Error 500

Hi Guys I am able not able to instaal xwiki. I am using tomcat 6 on ubuntu intrepid. Error I am gettting is *exception* javax.servlet.ServletException: com.xpn.xwiki.XWikiException: Error number 3 in 0: Could not initialize main XWiki context Wrapped Exception: Error number 3001 in 3: Cannot load class com.xpn.xwiki.store.migration.hibernate.XWikiHibernateMigrationManager from param xwiki.store.migration.manager.class Wrapped Exception: Error number 0 in 3: Exception while hibernate execute Wrapped Exception: Hibernate Dialect must be explicitly set org.apache.struts.action.RequestProcessor.processException(RequestProcessor.java:535) org.apache.struts.action.RequestProcessor.processActionPerform(RequestProcessor.java:433) org.apache.struts.action.RequestProcessor.process(RequestProcessor.java:236) org.apache.struts.action.ActionServlet.process(ActionServlet.java:1196) org.apache.struts.action.ActionServlet.doGet(ActionServlet.java:414) javax.servlet.http.HttpServlet.service(HttpServlet.java:617) javax.servlet.http.HttpServlet.service(HttpServlet.java:717) com.xpn.xwiki.wysiwyg.server.filter.ConversionFilter.doFilter(ConversionFilter.java:155) com.xpn.xwiki.web.ActionFilter.doFilter(ActionFilter.java:111) com.xpn.xwiki.plugin.webdav.XWikiDavFilter.doFilter(XWikiDavFilter.java:68) com.xpn.xwiki.web.SavedRequestRestorerFilter.doFilter(SavedRequestRestorerFilter.java:295) com.xpn.xwiki.web.SetCharacterEncodingFilter.doFilter(SetCharacterEncodingFilter.java:112) *root cause* com.xpn.xwiki.XWikiException: Error number 3 in 0: Could not initialize main XWiki context Wrapped Exception: Error number 3001 in 3: Cannot load class com.xpn.xwiki.store.migration.hibernate.XWikiHibernateMigrationManager from param xwiki.store.migration.manager.class Wrapped Exception: Error number 0 in 3: Exception while hibernate execute Wrapped Exception: Hibernate Dialect must be explicitly set com.xpn.xwiki.XWiki.getMainXWiki(XWiki.java:327) com.xpn.xwiki.XWiki.getXWiki(XWiki.java:388) com.xpn.xwiki.web.XWikiAction.execute(XWikiAction.java:135) com.xpn.xwiki.web.XWikiAction.execute(XWikiAction.java:115) org.apache.struts.action.RequestProcessor.processActionPerform(RequestProcessor.java:431) org.apache.struts.action.RequestProcessor.process(RequestProcessor.java:236) org.apache.struts.action.ActionServlet.process(ActionServlet.java:1196) org.apache.struts.action.ActionServlet.doGet(ActionServlet.java:414) javax.servlet.http.HttpServlet.service(HttpServlet.java:617) javax.servlet.http.HttpServlet.service(HttpServlet.java:717) com.xpn.xwiki.wysiwyg.server.filter.ConversionFilter.doFilter(ConversionFilter.java:155) com.xpn.xwiki.web.ActionFilter.doFilter(ActionFilter.java:111) com.xpn.xwiki.plugin.webdav.XWikiDavFilter.doFilter(XWikiDavFilter.java:68) com.xpn.xwiki.web.SavedRequestRestorerFilter.doFilter(SavedRequestRestorerFilter.java:295) com.xpn.xwiki.web.SetCharacterEncodingFilter.doFilter(SetCharacterEncodingFilter.java:112) Please help me to getover from this error. -arvind