[xwiki-users] Post-upgrade issue

After upgrading from 2.3 to 2.4M1 there are lots of text strings everywhere on every page. They look like this: $xwiki.ssfx.use('js/xwiki/widgets/jumpToPage.css', true) $xwiki.jsfx.use('uicomponents/widgets/confirmationBox.js', true) $xwiki.ssfx.use('uicomponents/widgets/confirmationBox.css', true) $xwiki.jsfx.use('uicomponents/widgets/confirmedAjaxRequest.js', true) $xwiki.jsfx.use('uicomponents/widgets/notification.js', true) $xwiki.ssfx.use('uicomponents/widgets/notification.css', true) (snipped) It's an easy-to-edit website that will help you work better together. This Wiki is made of pages sorted by spaces. You're currently in the Main space, looking at its home page (WebHome). $xwiki.ssx.use('Main.Dashboard') Also, there are exceptions java.lang.NullPointerException in logs and lines like this: [#|2010-06-13T12:59:22.015+0700|INFO|sun-appserver2.1| javax.enterprise.system.stream.out| _ThreadID=17;_ThreadName=http://metrolace.ru/bin/view/Main/;| 2010-06-13 12:59:22,015 [http://metrolace.ru/bin/view/Main/] ERROR internal.DefaultVelocityEngine - Left side ($tagCount.size()) of '>' operation has null value at velocity macro[line 54, column 24]|#] What's going on? Did I something wrong while updating?