Can't delete a page

Detailed information:

Error number 0 in 11: Uncaught exception
Wrapped Exception: Could not initialize class org.hibernate.util.GetGeneratedKeysHelper
com.xpn.xwiki.XWikiException: Error number 0 in 11: Uncaught exception
Wrapped Exception: Could not initialize class org.hibernate.util.GetGeneratedKeysHelper
at com.xpn.xwiki.web.XWikiAction.execute(XWikiAction.java:240)
at com.xpn.xwiki.web.XWikiAction.execute(XWikiAction.java:117)
at org.apache.struts.action.RequestProcessor.processActionPerform(RequestProcessor.java:431)
at org.apache.struts.action.RequestProcessor.process(RequestProcessor.java:236)
at org.apache.struts.action.ActionServlet.process(ActionServlet.java:1196)
at org.apache.struts.action.ActionServlet.doGet(ActionServlet.java:414)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:621)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:722)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:304)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
at com.xpn.xwiki.web.ActionFilter.doFilter(ActionFilter.java:129)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
at com.xpn.xwiki.wysiwyg.server.filter.ConversionFilter.doFilter(ConversionFilter.java:152)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
at com.xpn.xwiki.plugin.webdav.XWikiDavFilter.doFilter(XWikiDavFilter.java:68)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
at org.xwiki.container.servlet.filters.internal.SavedRequestRestorerFilter.doFilter(SavedRequestRestorerFilter.java:218)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
at org.xwiki.container.servlet.filters.internal.SetCharacterEncodingFilter.doFilter(SetCharacterEncodingFilter.java:112)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:240)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:164)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:498)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:164)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:100)
at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:562)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:394)
at org.apache.coyote.http11.Http11AprProcessor.process(Http11AprProcessor.java:284)
at org.apache.coyote.http11.Http11AprProtocol$Http11ConnectionHandler.process(Http11AprProtocol.java:322)
at org.apache.tomcat.util.net.AprEndpoint$SocketProcessor.run(AprEndpoint.java:1714)
at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)

Wrapped Exception:

java.lang.NoClassDefFoundError: Could not initialize class org.hibernate.util.GetGeneratedKeysHelper
at org.hibernate.jdbc.AbstractBatcher.getPreparedStatement(AbstractBatcher.java:495)
at org.hibernate.jdbc.AbstractBatcher.prepareStatement(AbstractBatcher.java:94)
at org.hibernate.id.IdentityGenerator$GetGeneratedKeysDelegate.prepare(IdentityGenerator.java:69)
at org.hibernate.id.insert.AbstractReturningDelegate.performInsert(AbstractReturningDelegate.java:30)
at org.hibernate.persister.entity.AbstractEntityPersister.insert(AbstractEntityPersister.java:2163)
at org.hibernate.persister.entity.AbstractEntityPersister.insert(AbstractEntityPersister.java:2643)
at org.hibernate.action.EntityIdentityInsertAction.execute(EntityIdentityInsertAction.java:51)
at org.hibernate.engine.ActionQueue.execute(ActionQueue.java:279)
at org.hibernate.event.def.AbstractSaveEventListener.performSaveOrReplicate(AbstractSaveEventListener.java:298)
at org.hibernate.event.def.AbstractSaveEventListener.performSave(AbstractSaveEventListener.java:181)
at org.hibernate.event.def.AbstractSaveEventListener.saveWithGeneratedId(AbstractSaveEventListener.java:107)
at org.hibernate.event.def.DefaultSaveOrUpdateEventListener.saveWithGeneratedOrRequestedId(DefaultSaveOrUpdateEventListener.java:187)
at org.hibernate.event.def.DefaultSaveEventListener.saveWithGeneratedOrRequestedId(DefaultSaveEventListener.java:33)
at org.hibernate.event.def.DefaultSaveOrUpdateEventListener.entityIsTransient(DefaultSaveOrUpdateEventListener.java:172)
at org.hibernate.event.def.DefaultSaveEventListener.performSaveOrUpdate(DefaultSaveEventListener.java:27)
at org.hibernate.event.def.DefaultSaveOrUpdateEventListener.onSaveOrUpdate(DefaultSaveOrUpdateEventListener.java:70)
at org.hibernate.impl.SessionImpl.fireSave(SessionImpl.java:535)
at org.hibernate.impl.SessionImpl.save(SessionImpl.java:523)
at org.hibernate.impl.SessionImpl.save(SessionImpl.java:519)
at com.xpn.xwiki.store.XWikiHibernateRecycleBinStore$1.doInHibernate(XWikiHibernateRecycleBinStore.java:73)
at com.xpn.xwiki.store.XWikiHibernateBaseStore.execute(XWikiHibernateBaseStore.java:1063)
at com.xpn.xwiki.store.XWikiHibernateBaseStore.executeWrite(XWikiHibernateBaseStore.java:1115)
at com.xpn.xwiki.store.XWikiHibernateRecycleBinStore.saveToRecycleBin(XWikiHibernateRecycleBinStore.java:69)
at com.xpn.xwiki.XWiki.deleteDocument(XWiki.java:4333)
at com.xpn.xwiki.XWiki.deleteAllDocuments(XWiki.java:6349)
at com.xpn.xwiki.XWiki.deleteAllDocuments(XWiki.java:6341)
at com.xpn.xwiki.web.DeleteAction.action(DeleteAction.java:94)
at com.xpn.xwiki.web.XWikiAction.execute(XWikiAction.java:215)
at com.xpn.xwiki.web.XWikiAction.execute(XWikiAction.java:117)
at org.apache.struts.action.RequestProcessor.processActionPerform(RequestProcessor.java:431)
at org.apache.struts.action.RequestProcessor.process(RequestProcessor.java:236)
at org.apache.struts.action.ActionServlet.process(ActionServlet.java:1196)
at org.apache.struts.action.ActionServlet.doGet(ActionServlet.java:414)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:621)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:722)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:304)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
at com.xpn.xwiki.web.ActionFilter.doFilter(ActionFilter.java:129)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
at com.xpn.xwiki.wysiwyg.server.filter.ConversionFilter.doFilter(ConversionFilter.java:152)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
at com.xpn.xwiki.plugin.webdav.XWikiDavFilter.doFilter(XWikiDavFilter.java:68)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
at org.xwiki.container.servlet.filters.internal.SavedRequestRestorerFilter.doFilter(SavedRequestRestorerFilter.java:218)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
at org.xwiki.container.servlet.filters.internal.SetCharacterEncodingFilter.doFilter(SetCharacterEncodingFilter.java:112)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:240)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:164)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:498)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:164)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:100)
at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:562)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:394)
at org.apache.coyote.http11.Http11AprProcessor.process(Http11AprProcessor.java:284)
at org.apache.coyote.http11.Http11AprProtocol$Http11ConnectionHandler.process(Http11AprProtocol.java:322)
at org.apache.tomcat.util.net.AprEndpoint$SocketProcessor.run(AprEndpoint.java:1714)
at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)