I am getting the following error when trying to insert the new task or event through API...

"<?xml version=\"1.0\" encoding=\"UTF-8\" ?>\r\n<response uri=\"/crm/private/xml/Tasks/insertRecords\"><error><code>4401</code><message>Unable to populate data, please check if mandatory value is entered correctly.</message></error></response>\r\n"

Here is my xml --

<?xml version=\"1.0\"?>\n<Tasks>\n  <row no=\"1\">\n    <FL val=\"Subject\">Call</FL>\n    <FL val=\"Status\">In Progress</FL>\n    <FL val=\"Priority\">Highest</FL>\n    <FL val=\"Send Notification Email\">false</FL>\n  </row>\n</Tasks>\n