Hello, could someone please help me with the following error: 16.01.2013 12:36:11 org.apache.catalina.core.StandardWrapperValve invoke SCHWERWIEGEND: Servlet.service() for servlet [action] in context with path [/xwiki] threw exception [com.xpn.xwiki.XWikiException: Error number 3 in 0: Could not initialize main XWiki context Wrapped Exception: Error number 3202 in 3: Exception while reading document [xwiki:XWiki.TagClass] Wrapped Exception: Error number 3301 in 3: Exception while switching to database xwiki Wrapped Exception: Database xwiki needs migration(s), it could not be safely used!] with root cause com.xpn.xwiki.store.migration.MigrationRequiredException: Database xwiki needs migration(s), it could not be safely used! at com.xpn.xwiki.store.migration.AbstractDataMigrationManager.checkDatabase(AbstractDataMigrationManager.java:442) at com.xpn.xwiki.store.XWikiHibernateBaseStore.setDatabase(XWikiHibernateBaseStore.java:678) at com.xpn.xwiki.store.XWikiHibernateBaseStore.beginTransaction(XWikiHibernateBaseStore.java:853) at com.xpn.xwiki.store.XWikiHibernateBaseStore.beginTransaction(XWikiHibernateBaseStore.java:785) at com.xpn.xwiki.store.XWikiHibernateStore.loadXWikiDoc(XWikiHibernateStore.java:749) at com.xpn.xwiki.store.XWikiCacheStore.loadXWikiDoc(XWikiCacheStore.java:290) at com.xpn.xwiki.XWiki.getDocument(XWiki.java:1404) at com.xpn.xwiki.XWiki.getDocument(XWiki.java:1447) at com.xpn.xwiki.XWiki.initializeMandatoryClasses(XWiki.java:824) at com.xpn.xwiki.XWiki.initXWiki(XWiki.java:794) at com.xpn.xwiki.XWiki.<init>(XWiki.java:735) at com.xpn.xwiki.XWiki.getMainXWiki(XWiki.java:394) at com.xpn.xwiki.XWiki.getXWiki(XWiki.java:483) at com.xpn.xwiki.web.XWikiAction.execute(XWikiAction.java:136) at com.xpn.xwiki.web.XWikiAction.execute(XWikiAction.java:116) 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:306) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210) at com.xpn.xwiki.web.ActionFilter.doFilter(ActionFilter.java:120) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:244) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210) at org.xwiki.wysiwyg.server.filter.ConversionFilter.doFilter(ConversionFilter.java:144) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:244) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210) at com.xpn.xwiki.plugin.webdav.XWikiDavFilter.doFilter(XWikiDavFilter.java:66) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:244) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210) at org.xwiki.container.servlet.filters.internal.SavedRequestRestorerFilter.doFilter(SavedRequestRestorerFilter.java:208) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:244) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210) at org.xwiki.container.servlet.filters.internal.SetCharacterEncodingFilter.doFilter(SetCharacterEncodingFilter.java:111) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:244) 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:161) 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:541) at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118) at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:383) 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:1684) 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) I've tried everything I found so far, but nothing changed the outcome. With best regards Robert -- View this message in context: http://xwiki.475771.n2.nabble.com/Failed-migration-from-3-0-to-4-3-1-tp75833... Sent from the XWiki- Users mailing list archive at Nabble.com.