Form API Ajax and managed_file upload loses form_state

you can get the element to use a callback instead of a path without hacking core. Add a #process element to your managed_file:

$form['doc1'] = array(
  '#type' => 'managed_file',
  '#process' => array('fix_ajax_upload'),
);

and then use that function to alter the managed_file element:

function fix_ajax_upload($element, &$form_state, $form) {

  // process $element as normal
  $element = file_managed_file_process($element, $form_state, $form);

  // remove path, add callback
  unset($element['upload_button']['#ajax']['path']);
  $element['upload_button']['#ajax']['callback'] = 'file_ajax_upload_callback';

  return $element;

}

Thanks for taking the time to explain your fix for this. I can't seem to get this working and it's a nightmare because my client has seen the upload field work previously and now I'm saying they can't have it, I'm explaining there is a bug and they are clueless and now think their website has a virus. But anyway, I have copied the file_ajax_upload function, but not sure if I have made the correct modifications as I am getting an error which states - Notice: Undefined index: #suffix in file_ajax_upload_callback()

Here is the modified function

function file_ajax_upload_callback($form, $form_state) {
  $form_parents = isset($form_state['triggering_element']['#parents'][0]) ? array($form_state['triggering_element']['#parents'][0]) : array($form_state['triggering_element'] ['#array_parents'][0]);
  $form_build_id = $form['#build_id'];

  if (!isset($form_build_id) || empty($form_build_id)) {
    // Invalid request.
    drupal_set_message(t('An unrecoverable error occurred. The uploaded file likely exceeded the maximum file size (@size) that this server supports.', array('@size' => format_size(file_upload_max_size()))), 'error');
    $commands = array();
    $commands[] = ajax_command_replace(NULL, theme('status_messages'));
    return array('#type' => 'ajax', '#commands' => $commands);
  }

  

  if (!$form) {
    // Invalid form_build_id.
    drupal_set_message(t('An unrecoverable error occurred. Use of this form has expired. Try reloading the page and submitting again.'), 'error');
    $commands = array();
    $commands[] = ajax_command_replace(NULL, theme('status_messages'));
    return array('#type' => 'ajax', '#commands' => $commands);
  }

  // Get the current element and count the number of files.
  $current_element = $form;
  foreach ($form_parents as $parent) {
    $current_element = $current_element[$parent];
  }
  $current_file_count = isset($current_element['#file_upload_delta']) ? $current_element['#file_upload_delta'] : 0;

  // Process user input. $form and $form_state are modified in the process.
  drupal_process_form($form['#form_id'], $form, $form_state);

  // Retrieve the element to be rendered.
  foreach ($form_parents as $parent) {
    $form = $form[$parent];
  }

  // Add the special Ajax class if a new file was added.
  if (isset($form['#file_upload_delta']) && $current_file_count < $form['#file_upload_delta']) {
    $form[$current_file_count]['#attributes']['class'][] = 'ajax-new-content';
  }
  // Otherwise just add the new content class on a placeholder.
  else {
    $form['#suffix'] .= '<span class="ajax-new-content"></span>';
  }

  $form['#prefix'] .= theme('status_messages');
  $output = drupal_render($form);
  $js = drupal_add_js();
  $settings = drupal_array_merge_deep_array($js['settings']['data']);

  $commands[] = ajax_command_replace(NULL, $output, $settings);
  return array('#type' => 'ajax', '#commands' => $commands);
}

Here is the other part of my code, if anyone can help with this I am willing to pay, please leave a message

/**
 * Implements hook_form_alter().
 */
function form_alter_form_alter(&$form, &$form_state, $form_id) {
    
    if ($form_id === 'commerce_cart_add_to_cart_form_CHQU73IYWMGr6uPDEWPhR9tSmUbATM6TU2DS-v1hkHU') {
    	$form['#after_build'][] = 'form_alter_after_build'; 
    }

}

function form_alter_after_build($form, &$form_state) {
	$form['line_item_fields']['field_upload_images'][LANGUAGE_NONE][0]['#process'][] = 'fix_ajax_upload';

	return $form;
}


function fix_ajax_upload($element, &$form_state, $form) {
  
	$element = file_managed_file_process($element, $form_state, $form);
	unset($element['upload_button']['#ajax']['path']);
	$element['upload_button']['#ajax']['callback'] = 'form_alter_ajax_upload_callback';
	return $element;

}