Q:

Error: No Multipart boundary is found when passing form-data via AJAX

I am passing form-data via AJAX:
var data = new FormData();
data.append('username', username);
data.append('company', company);

$.ajax({
   url: 'path to service',
   type: 'POST',
   enctype: 'multipart/form-data',
   async: true,
   contentType: 'multipart/form-data',
   processData: false,
   data: data,
   cache: false,
   success: function(data){

   },
   error: function(error){

   }
});

But I get an error: 

the request was rejected because no multipart boundary was found

A:

You should set the contentType to false, which will force jQuery to generate the content-type header, including the mandatory multipart boundary.
EDIT: just realised it was already answered in: How to send FormData objects with Ajax-requests in jQuery?

