I have a not very easy installation on an Internationalized domain name ("ä" German). With the settings under dm_admin_page I get the following error message:
Warning: call_user_func_array () Expects parameter 1 to be a valid callback, function 'dm_admin_page' not found or invalid function name in /www/htdocs/xxx/wp-includes/plugin.php on line 406
What could that mean? Tried a lot, nothing helped.
Thanks for support.