_oa_core_build_visibility_links error

That function is used for two panes, 'Content Visibility' and 'Visibility toolbar', the former has a required node context and later checks if $node->type is set

The function is passed a $node variable that based on ^ should be set to a node. Then it does the below checking, which should result in $section_node being set to a node (cause of the empty( check).

    if ($node->type == OA_SECTION_TYPE) {
      $section_node = $node;
    }
    else {
      $section_reference_field = field_get_items('node', $node, OA_SECTION_FIELD);
      $section_node = node_load($section_reference_field[0]['target_id']);
    }
    if (empty($section_node)) {
      $section_node = $node;
    }

      $data['public'] = (($section_node->type != OA_SECTION_TYPE) || oa_core_section_is_public($section_node))
        && empty($visibility[0]['value']);

Is the line 495

So... how is that function on your install getting an invalid $section_node? Don't see how that could be happening unless something else is causing it or such, hard to debug without being able to reproducing it myself

the output of

static $once;
if (!isset($section_node->type) && !$once) {
  $once = TRUE;
  drupal_set_message(print_r(debug_backtrace(), 1));
}

would be helpful