Error whenever editing a page

    Error number 13007 in 3: Exception while loading lock
Wrapped Exception: a different object with the same identifier value was already associated with the session: [com.xpn.xwiki.doc.XWikiLock#104408758]
com.xpn.xwiki.XWikiException: Error number 13007 in 3: Exception while loading lock
Wrapped Exception: a different object with the same identifier value was already associated with the session: [com.xpn.xwiki.doc.XWikiLock#104408758]
	at com.xpn.xwiki.store.XWikiHibernateStore.loadLock(XWikiHibernateStore.java:1698)
	at com.xpn.xwiki.store.XWikiCacheStore.loadLock(XWikiCacheStore.java:540)
	at com.xpn.xwiki.doc.XWikiDocument.removeLock(XWikiDocument.java:4209)
	at com.xpn.xwiki.web.SaveAction.save(SaveAction.java:179)
	at com.xpn.xwiki.web.SaveAction.action(SaveAction.java:193)
	at com.xpn.xwiki.web.XWikiAction.execute(XWikiAction.java:213)
	at com.xpn.xwiki.web.XWikiAction.execute(XWikiAction.java:115)
	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.doPost(ActionServlet.java:432)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:754)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:847)
	at org.apache.catalina.core.ApplicationFilterChain.servletService(ApplicationFilterChain.java:427)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:333)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:214)
	at com.xpn.xwiki.wysiwyg.server.filter.ConversionFilter.doFilter(ConversionFilter.java:155)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:246)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:214)
	at com.xpn.xwiki.web.ActionFilter.doFilter(ActionFilter.java:117)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:246)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:214)
	at com.xpn.xwiki.plugin.webdav.XWikiDavFilter.doFilter(XWikiDavFilter.java:68)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:246)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:214)
	at com.xpn.xwiki.web.SavedRequestRestorerFilter.doFilter(SavedRequestRestorerFilter.java:295)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:246)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:214)
	at com.xpn.xwiki.web.SetCharacterEncodingFilter.doFilter(SetCharacterEncodingFilter.java:112)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:246)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:214)
	at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:313)
	at org.apache.catalina.core.StandardContextValve.invokeInternal(StandardContextValve.java:287)
	at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:218)
	at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:648)
	at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:593)
	at com.sun.enterprise.web.WebPipeline.invoke(WebPipeline.java:94)
	at com.sun.enterprise.web.PESessionLockingStandardPipeline.invoke(PESessionLockingStandardPipeline.java:98)
	at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:222)
	at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:648)
	at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:593)
	at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:587)
	at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:1096)
	at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:166)
	at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:648)
	at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:593)
	at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:587)
	at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:1096)
	at org.apache.coyote.tomcat5.CoyoteAdapter.service(CoyoteAdapter.java:288)
	at com.sun.enterprise.web.connector.grizzly.DefaultProcessorTask.invokeAdapter(DefaultProcessorTask.java:647)
	at com.sun.enterprise.web.connector.grizzly.DefaultProcessorTask.doProcess(DefaultProcessorTask.java:579)
	at com.sun.enterprise.web.connector.grizzly.DefaultProcessorTask.process(DefaultProcessorTask.java:831)
	at com.sun.enterprise.web.connector.grizzly.DefaultReadTask.executeProcessorTask(DefaultReadTask.java:341)
	at com.sun.enterprise.web.connector.grizzly.DefaultReadTask.doTask(DefaultReadTask.java:263)
	at com.sun.enterprise.web.connector.grizzly.DefaultReadTask.doTask(DefaultReadTask.java:214)
	at com.sun.enterprise.web.portunif.PortUnificationPipeline$PUTask.doTask(PortUnificationPipeline.java:380)
	at com.sun.enterprise.web.connector.grizzly.TaskBase.run(TaskBase.java:265)
	at com.sun.enterprise.web.connector.grizzly.ssl.SSLWorkerThread.run(SSLWorkerThread.java:106)


Wrapped Exception:

org.hibernate.NonUniqueObjectException: a different object with the same identifier value was already associated with the session: [com.xpn.xwiki.doc.XWikiLock#104408758]
	at org.hibernate.event.def.DefaultLoadEventListener.load(DefaultLoadEventListener.java:176)
	at org.hibernate.event.def.DefaultLoadEventListener.proxyOrLoad(DefaultLoadEventListener.java:223)
	at org.hibernate.event.def.DefaultLoadEventListener.onLoad(DefaultLoadEventListener.java:126)
	at org.hibernate.impl.SessionImpl.fireLoad(SessionImpl.java:905)
	at org.hibernate.impl.SessionImpl.load(SessionImpl.java:811)
	at com.xpn.xwiki.store.XWikiHibernateStore.loadLock(XWikiHibernateStore.java:1691)
	at com.xpn.xwiki.store.XWikiCacheStore.loadLock(XWikiCacheStore.java:540)
	at com.xpn.xwiki.doc.XWikiDocument.removeLock(XWikiDocument.java:4209)
	at com.xpn.xwiki.web.SaveAction.save(SaveAction.java:179)
	at com.xpn.xwiki.web.SaveAction.action(SaveAction.java:193)
	at com.xpn.xwiki.web.XWikiAction.execute(XWikiAction.java:213)
	at com.xpn.xwiki.web.XWikiAction.execute(XWikiAction.java:115)
	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.doPost(ActionServlet.java:432)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:754)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:847)
	at org.apache.catalina.core.ApplicationFilterChain.servletService(ApplicationFilterChain.java:427)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:333)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:214)
	at com.xpn.xwiki.wysiwyg.server.filter.ConversionFilter.doFilter(ConversionFilter.java:155)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:246)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:214)
	at com.xpn.xwiki.web.ActionFilter.doFilter(ActionFilter.java:117)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:246)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:214)
	at com.xpn.xwiki.plugin.webdav.XWikiDavFilter.doFilter(XWikiDavFilter.java:68)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:246)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:214)
	at com.xpn.xwiki.web.SavedRequestRestorerFilter.doFilter(SavedRequestRestorerFilter.java:295)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:246)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:214)
	at com.xpn.xwiki.web.SetCharacterEncodingFilter.doFilter(SetCharacterEncodingFilter.java:112)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:246)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:214)
	at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:313)
	at org.apache.catalina.core.StandardContextValve.invokeInternal(StandardContextValve.java:287)
	at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:218)
	at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:648)
	at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:593)
	at com.sun.enterprise.web.WebPipeline.invoke(WebPipeline.java:94)
	at com.sun.enterprise.web.PESessionLockingStandardPipeline.invoke(PESessionLockingStandardPipeline.java:98)
	at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:222)
	at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:648)
	at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:593)
	at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:587)
	at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:1096)
	at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:166)
	at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:648)
	at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:593)
	at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:587)
	at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:1096)
	at org.apache.coyote.tomcat5.CoyoteAdapter.service(CoyoteAdapter.java:288)
	at com.sun.enterprise.web.connector.grizzly.DefaultProcessorTask.invokeAdapter(DefaultProcessorTask.java:647)
	at com.sun.enterprise.web.connector.grizzly.DefaultProcessorTask.doProcess(DefaultProcessorTask.java:579)
	at com.sun.enterprise.web.connector.grizzly.DefaultProcessorTask.process(DefaultProcessorTask.java:831)
	at com.sun.enterprise.web.connector.grizzly.DefaultReadTask.executeProcessorTask(DefaultReadTask.java:341)
	at com.sun.enterprise.web.connector.grizzly.DefaultReadTask.doTask(DefaultReadTask.java:263)
	at com.sun.enterprise.web.connector.grizzly.DefaultReadTask.doTask(DefaultReadTask.java:214)
	at com.sun.enterprise.web.portunif.PortUnificationPipeline$PUTask.doTask(PortUnificationPipeline.java:380)
	at com.sun.enterprise.web.connector.grizzly.TaskBase.run(TaskBase.java:265)
	at com.sun.enterprise.web.connector.grizzly.ssl.SSLWorkerThread.run(SSLWorkerThread.java:106)