"Add Section Content" panel is empty

Summary

The "Add Section Content" Panel (pictured in attached image) no longer works due to the commit mentioned in comment #5 below.

Steps to recreate

From a fresh install:

1. Create a new space
2. Create a new section
3. 'Customize the page' using the in-place editor
4. Add the 'Add Section Content' pane to the content (found under the 'Open Atrium' section)
5. Save the changes and view the page
6. There is a blank space where the content creation button should be

Error message received

Checking the error log I see the following:
Warning: array_merge(): Argument #1 is not an array in command_buttons_get_button_class() (line 779 of /var/www/html/transtoolkit/docroot/profiles/openatrium/modules/contrib/command_buttons/command_buttons.module).
Notice: Undefined variable: classes in command_buttons_get_button_class() (line 779 of /var/www/html/transtoolkit/docroot/profiles/openatrium/modules/contrib/command_buttons/command_buttons.module).
Warning: Invalid argument supplied for foreach() in command_buttons_entity_view() (line 601 of /var/www/html/transtoolkit/docroot/profiles/openatrium/modules/contrib/command_buttons/command_buttons.module).

Original report

Latest Upgrade affected my custom panel panes module, because it was based on OA's add content panel. Error states the panel is Empty or Inaccessible.

I upgraded to Open Atrium 2.19 and my custom pane is no longer working. When I am editing my panels with IPE the panel (that should have my custom pane) says: Empty or Inaccessible. When I try to add that pane, it still exists as an option, and I get all the fields for settings in that panel, but nothing is rendering. Somehow the content is now considered empty.

Hopefully, this will reveal a necessary edit for others as well in their custom panel panes.

Here is my code:

<?php
/**
 * @file oa_notifications_pane.inc
 */

$plugin = array(
  'title' => t('OAK Add Section Content'),
  'description' => t('Create section content according to allowed content options'),
  'single' => TRUE,
  'category' => array(t('OAK CCT'), -9),
  'edit form' => 'oak_cct_oak_cct_ascp_settings_form',
  'render callback' => 'oak_cct_oak_cct_ascp_render',
  'required context' => new ctools_context_required(t('Node'), 'node'),
  'defaults' => array(
    'description' => '', 
    'image' => '',
    ),
);


/**
 * Provides the form for the widget.
 */
function oak_cct_oak_cct_ascp_settings_form($form, &$form_state) {
  $conf = $form_state['conf'];
  $form['description'] = array(
    '#type' => 'textfield',
    '#title' => t('description text'),
    '#size' => 50,
    '#description' => t('A description.'),
    '#default_value' => !empty($conf['description']) ? $conf['description'] : 'default description',
  );
  $form['image'] = array(
    '#type' => 'textfield',
    '#title' => t('image text'),
    '#size' => 50,
    '#description' => t('An image.'),
    '#default_value' => !empty($conf['image']) ? $conf['image'] : 'default image text',
  );
  // no submit
  return $form;
}


/**
 * Renders the widget.
 */
function oak_cct_oak_cct_ascp_render($subtype, $conf, $args, $context) {
  $block_description = $conf['description'];
  $block_image = $conf['image'];

  $node = $context->data;
  if ($node) {
    $node_types = oa_buttons_get_command_buttons($node);
    if (!empty($node_types)) {

      $buttons = command_buttons_machine_name_load(array_keys($node_types));
      
      // display only if have access to button
      $access = FALSE;
      foreach ($buttons as $key => $button) {
        if (node_access('create', $buttons[$key]->name)) {
          $access = TRUE;
        }


      }

      $item_list = array();
      $classes = array(
        'item_class' => array(
          'btn btn-primary btn-green btn-mini',
          'oa-button',
         ),
        'wrapper_class' => array(
          'oa-buttons',
        ),
      );
      $block = new stdClass();
      if($access){
        $block->title = t('Create Content');
      
	$block->content = "<p>" . $conf['description'] . "</p>" . command_buttons_render_buttons($buttons, $classes, $node_types);
	}
      //$block->description = $conf['description'];
      //$block->image = $conf['image'];
    }
  }
  return $block;
}


/**
 * Submit function, note anything in the formstate[conf] automatically gets saved 
 */
function oak_cct_oak_cct_ascp_settings_form_submit($form, &$form_state) {
  foreach (array_keys($form_state['values']) as $key) {
    if (isset($form_state['values'][$key])) {
      $form_state['conf'][$key] = $form_state['values'][$key];
    }
  }
}

Here are results for various printed variables:

$node_types = 
Array
(
    [oa_wiki_page:11] => Array
        (
            [value] => oa_wiki_page
            [provider_type] => oa_section
            [id] => 11
        )

)

$buttons = 
Array
(
)

It seems to me that the issue could be here:

$buttons = command_buttons_machine_name_load(array_keys($node_types));

For some reason, this function is now giving an empty $buttons array, where before the update, it was not empty.