[rules-users] Avoiding log or error messages on console

Hi everybody: I'm developing a Drools based application which has to show no messages on console, but on log files or so. I've diverted these kind of messages to a log file, but there is one at the beginning of the application, when the change set is read... (null: 6, 188): cvc-elt.1: Cannot find the declaration of element 'change-set'. ... which still appears on console. I've read that this message doesn't affect rule engine behaviour, but I would like it not to be shown on console. Does anybody know how can I solve this problem? Thank you in advance. Best regards, Manuel Ortiz.