Ajax error when trying to create a (new) variant in menu's

Moving this to the main issue queue.

Confirmed. I can reproduce the error. Working on a fix.

Found a fix. @eljay can you please test if the fix below works?

1. Edit /profile/restaurant/modules/restaurant/restaurant_menu.module.
2. Find the restaurant_menu_form_menu_node_form_alter function.
3. Add the following lines to the top of the function.

// Include node.pages.inc.
form_load_include($form_state, 'inc', 'node', 'node.pages');

Your function should look like this:

/**
 * Implements hook_form_FORM_ID_alter().
 */
function restaurant_menu_form_menu_node_form_alter(&$form, &$form_state, $form_id) {
  // Include node.pages.inc.
  form_load_include($form_state, 'inc', 'node', 'node.pages');

  // Get the site language.
  $language = isset($form['language']['#value']) ? $form['language']['#value'] : $form['#node']->language;

  // Hide locations field if restaurant_location module is disabled.
  if (!module_exists('restaurant_location')) {
    $form['field_menu_locations']['#access'] = FALSE;
  }
....

4. Reload the menu form and try adding a variant.

Ok I'll commit and push. Thanks.