Never use the expression "if obj" whenever obj is not a simple type.

bt5/erp5_credential/SkinTemplateItem/portal_skins/erp5_credential/ERP5Site_newOrganisationCredentialUpdate.xml

@@ -53,7 +53,7 @@
             <value> <string>"""Create a new credential update"""\n
 portal_status_message=""\n
 person = context.ERP5Site_getAuthenticatedMemberPersonValue()\n
-if not person:\n
+if person is None:\n
   portal_status_message = context.Base_translateString("Can\'t find corresponding person, it\'s not possible to update your credentials.")\n
 else:\n
   organisation = person.getSubordinationValue()\n

bt5/erp5_credential/SkinTemplateItem/portal_skins/erp5_credential/ERP5Site_newPersonCredentialUpdate.xml

@@ -53,7 +53,7 @@
             <value> <string>"""Create a credential update in relation with the person object of current user"""\n
 person = context.ERP5Site_getAuthenticatedMemberPersonValue()\n
 \n
-if not person:\n
+if person is None:\n
   portal_status_message = context.Base_translateString("Can\'t find corresponding person, it\'s not possible to update your credentials.")\n
 else:\n
   # create the credential update\n

bt5/erp5_credential/bt/revision

-359
\ No newline at end of file
+360
\ No newline at end of file