[SOLVED][Drupal Multiupload Filefield Widget] Notice: Undefined index: #size in file_managed_file_process() (line 446 of .../file.module)

Here is the solution.

• Update the multiupload_filefield_widget.module file with the following code.
  

   30,
  
  
  44:  function mfw_managed_file_process($element, &$form_state, &$form) {
  +  $element['#size']=30; //just element width =)
  ?>

• Remember to create a patch when you edit the module
• Some Drupal 7.14 users reported success with the following code

 function mfw_managed_file_process($element, &$form_state, &$form) {
+  if (empty($element['#size'])) $element['#size'] = NULL;
   $element = file_managed_file_process($element, $form_state, $form);
   $element['upload']['#attributes'] = array('multiple' => 'multiple');
   $element['upload']['#name'] = 'files_' . implode('_', $element['#parents']) . '[]';

Hope that helps.