Subwikis migration fail

2017-04-25 11:19:20,376 [XWiki initialization] ERROR .HibernateDataMigrationManager - Failed to migrate database [eduorganizer]... 
java.lang.NullPointerException: null
	at com.xpn.xwiki.XWiki.getPlugin(XWiki.java:5619)
	at com.xpn.xwiki.plugin.activitystream.impl.ActivityStreamConfiguration.useMainStore(ActivityStreamConfiguration.java:85)
	at com.xpn.xwiki.plugin.activitystream.internal.RecordableEventMigrator.shouldExecute(RecordableEventMigrator.java:89)
	at com.xpn.xwiki.store.migration.AbstractDataMigrationManager.getNeededMigrations(AbstractDataMigrationManager.java:771)
	at com.xpn.xwiki.store.migration.AbstractDataMigrationManager.migrateDatabase(AbstractDataMigrationManager.java:741)
	at com.xpn.xwiki.store.migration.AbstractDataMigrationManager.startMigrations(AbstractDataMigrationManager.java:674)
	at com.xpn.xwiki.store.migration.hibernate.HibernateDataMigrationManager.startMigrations(HibernateDataMigrationManager.java:355)
	at com.xpn.xwiki.store.migration.AbstractDataMigrationManager.startMigrationsOnlyOnce(AbstractDataMigrationManager.java:644)
	at com.xpn.xwiki.store.migration.AbstractDataMigrationManager.tryToProcceedToMigration(AbstractDataMigrationManager.java:621)
	at com.xpn.xwiki.store.migration.AbstractDataMigrationManager.checkDatabase(AbstractDataMigrationManager.java:538)
	at com.xpn.xwiki.store.XWikiHibernateBaseStore.setDatabase(XWikiHibernateBaseStore.java:765)
	at com.xpn.xwiki.store.XWikiHibernateBaseStore.beginTransaction(XWikiHibernateBaseStore.java:942)
	at com.xpn.xwiki.store.XWikiHibernateBaseStore.beginTransaction(XWikiHibernateBaseStore.java:873)
	at com.xpn.xwiki.store.XWikiHibernateStore.loadXWikiDoc(XWikiHibernateStore.java:865)
	at com.xpn.xwiki.store.XWikiCacheStore.loadXWikiDoc(XWikiCacheStore.java:280)
	at com.xpn.xwiki.XWiki.getDocument(XWiki.java:1817)
	at com.xpn.xwiki.XWiki.getDocument(XWiki.java:1870)
	at com.xpn.xwiki.XWiki.initializeMandatoryDocument(XWiki.java:1275)
	at com.xpn.xwiki.XWiki.initializeMandatoryDocuments(XWiki.java:1249)
	at com.xpn.xwiki.XWiki.initXWiki(XWiki.java:1188)
	at com.xpn.xwiki.XWiki.initXWiki(XWiki.java:1103)
	at com.xpn.xwiki.XWiki.<init>(XWiki.java:1076)
	at com.xpn.xwiki.internal.XWikiInitializerJob.runInternal(XWikiInitializerJob.java:117)
	at org.xwiki.job.AbstractJob.runInContext(AbstractJob.java:206)
	at org.xwiki.job.AbstractJob.run(AbstractJob.java:189)
	at java.lang.Thread.run(Thread.java:748)