I tried to migrate a xwiki 3.1.1 instance to 4.2. The database is postgresql 9.1 and the container is tomcat 7. Accessing the upgrade xwiki instance I got: Oct 14 21:00:30 odie local5.info [xwiki-c42] [] -- [http://xxx:xxx/xwiki/bin/view/Main/] com.xpn.xwiki.store.migration.hibernate.HibernateDataMigrationManager Running storage schema updates and migrations Oct 14 21:00:30 odie local5.info [xwiki-c42] [] -- [http://xxx:xxx/xwiki/bin/view/Main/] com.xpn.xwiki.store.migration.hibernate.HibernateDataMigrationManager Current storage version = [35100] Oct 14 21:00:30 odie local5.info [xwiki-c42] [] -- [http://xxx:xxx/xwiki/bin/view/Main/] com.xpn.xwiki.store.migration.hibernate.HibernateDataMigrationManager List of migrations that will be executed: Oct 14 21:00:30 odie local5.info [xwiki-c42] [] -- [http://xxx:xxx/xwiki/bin/view/Main/] com.xpn.xwiki.store.migration.hibernate.HibernateDataMigrationManager R35102XWIKI7771 - See http://jira.xwiki.org/browse/XWIKI-7771 Oct 14 21:00:30 odie local5.info [xwiki-c42] [] -- [http://xxx:xxx/xwiki/bin/view/Main/] com.xpn.xwiki.store.migration.hibernate.HibernateDataMigrationManager R40000XWIKI6990 - Convert document IDs to use the new improved hash algorithm. Oct 14 21:00:30 odie local5.info [xwiki-c42] [] -- [http://xxx:xxx/xwiki/bin/view/Main/] com.xpn.xwiki.store.migration.hibernate.HibernateDataMigrationManager R40001XWIKI7540 - See http://jira.xwiki.org/browse/XWIKI-7540 Oct 14 21:00:34 odie local5.info [xwiki-c42] [] -- [http://xxx:xxx/xwiki/bin/view/Main/] com.xpn.xwiki.store.migration.hibernate.R40000XWIKI6990DataMigration [R40000XWIKI6990] - 41 schema updates required. Oct 14 21:00:35 odie local5.info [xwiki-c42] [] -- [http://xxx:xxx/xwiki/bin/view/Main/] com.xpn.xwiki.store.migration.liquibase Successfully acquired change log lock Oct 14 21:00:35 odie local5.info [xwiki-c42] [] -- [http://xxx:xxx/xwiki/bin/view/Main/] com.xpn.xwiki.store.migration.liquibase Reading from databasechangelog Oct 14 21:00:35 odie local5.info [xwiki-c42] [] -- [http://xxx:xxx/xwiki/bin/view/Main/] com.xpn.xwiki.store.migration.liquibase Reading from databasechangelog Oct 14 21:00:35 odie local5.info [xwiki-c42] [] -- [http://xxx:xxx/xwiki/bin/view/Main/] com.xpn.xwiki.store.migration.liquibase Successfully released change log lock Oct 14 21:00:35 odie local5.info [xwiki-c42] [] -- [http://xxx:xxx/xwiki/bin/view/Main/] com.xpn.xwiki.store.migration.hibernate.HibernateDataMigrationManager Failed to migrate database [xwiki]... Oct 14 21:00:35 odie local5.info #011at [] -- com.xpn.xwiki.store.migration.hibernate.HibernateDataMigrationManager.updateSchema(HibernateDataMigrationManager.java:179) Oct 14 21:00:35 odie local5.info #011at [] -- com.xpn.xwiki.store.migration.AbstractDataMigrationManager.startMigrationsForDatabase(AbstractDataMigrationManager.java:545) Oct 14 21:00:35 odie local5.info #011at [] -- com.xpn.xwiki.store.migration.AbstractDataMigrationManager.startMigrations(AbstractDataMigrationManager.java:493) Oct 14 21:00:35 odie local5.info #011at [] -- com.xpn.xwiki.store.migration.hibernate.HibernateDataMigrationManager.startMigrations(HibernateDataMigrationManager.java:296) .... Oct 14 21:00:36 odie local5.warning [xwiki-c42] [] -- [http://xxx:xxx/xwiki/bin/view/Main/] org.apache.struts.action.RequestProcessor Unhandled Exception thrown: class com.xpn.xwiki.XWikiException Oct 14 21:00:36 odie local5.err Oct [] -- 14, 2012 9:00:36 PM org.apache.catalina.core.StandardWrapperValve invoke\SEVERE: 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.XWikiPreferences]\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:441)\.at com.xpn.xwiki.store.XWikiHibernateBaseStore.setDatabase(XWikiHibernateBaseStore.java:665)\.at com.xpn.xwiki.store.XWikiHibernateBaseStore.beginTransaction(XWikiHibernateBaseStore.java:813)\.at com.xpn Has anybody a hint what is going wrong ? Best Regards, H.-Dirk Schmitt -- Signature H.-Dirk Schmitt ------------------------------------------------------------------------ * H.-Dirk Schmitt <http://www.computer42.org>* Dipl.Math. eMail:/dirk.schmitt@computer42.org/ mobile:/+49 177 616 8564/ phone: /+49 2642 99 41 10/ fax: /+49 2642 99 41 15/ Kripper Str. 35, D-53489 Sinzig pgp: http://www.computer42.org/~dirk/OpenPGP-fingerprint.html <http://www.computer42.org/%7Edirk/OpenPGP-fingerprint.html>