Contains can not be used for String with the Expression editor -------------------------------------------------------------- Key: DROOLS-4340 URL: https://issues.jboss.org/browse/DROOLS-4340 Project: Drools Issue Type: Bug Reporter: Toni Rikkola Assignee: Toni Rikkola Priority: Critical Labels: drools-tools Use the expression editor and check for example person.name.contains("ABC"). Save, close the editor and reopen. "contains("ABC")" does not show up in the editor.