Error Code 4401 when inserting new Case

Error Code 4401 when inserting new Case

  1. <Cases>
  2.       <row no="1">
  3.             <FL val="WHOID" >000008000000000000</FL>
  4.             <FL val="Case Origin">Site web</FL>
  5.             <FL val="Email" >cktag@test.com</FL>
  6.             <FL val="Phone" >0546477748</FL>
  7.             <FL val="Description" >test</FL>
  8.             <FL val="Status" >Nouveau</FL>
  9.             <FL val="Subject" >test</FL>
  10.       </row>
  11. </Cases>
Hello when i try to insert a new Case like that i have this message :

4401 Unable to populate data, please check if mandatory value is entered correctly.

Can you help me ?