Hi, I'm testing XE 2.6 with XEM. My plugins/applications are - xwiki-application-application-manager-1.16.xar - xwiki-application-wiki-manager-1.22.xar - xwiki-enterprise-manager-application-xem-2.6.xar (corresponding .jar files are at WEB-INF\lib) Our Environment is Jboss 4.2.1 web server and Oracle 10g database. There is a problem with the Activity Stream at the homepages of the farm members. The "Activity Stream" keeps empty and there are some identical lines within the jboss console log: 15:50:59,267 ERROR [DefaultVelocityEngine] Left side ($events.size()) of '>' operation has null value at unknown namespace[line 648, column 21] After disabling the "Right column" of the Dashboard page the error does not appeare. The error does not happen at the master wiki of the farm (http://localhost/xwiki/bin/view/Main/Dashboard), only at all member wikis. Do you have a hint where to look further? Thanks, Rudi -- View this message in context: http://xwiki.475771.n2.nabble.com/i-got-an-null-value-at-unknown-namespace-… Sent from the XWiki- Users mailing list archive at Nabble.com.