I guess that SEF is not working correctly. Please check if the menu link to uddeIM is still correct (so it has a valid ItemID), that your .htaccess is working properly and Joomla SEF in enabled.
In case it does not work disable SEF completely and check the URL (it should look like "index.php?option=com_uddeim&Itemid=125").
Im most cases the problem occurs when a 3rd party SEF is used that is not configured properly.
uddeIM & uddePF Development
CB Language Workgroup
CB 3rd Party Developer