Undefined index: format in views_object->unpack_options() (line 143 of /sites/all/modules/views

Thank you, neoglez. Here is the export, there are no customizations, it is the OG view. Also, since I posted, the folks on the commerce thread dealing with the exact same message suggested I see this thread: http://drupal.org/node/1034532

Not sure if it will help or not. Thanks again, I appreciate your looking at it.

$view = new view;
$view->name = 'og_nodes';
$view->description = 'Show all content (nodes) of a group.';
$view->tag = 'og';
$view->base_table = 'node';
$view->human_name = 'OG content';
$view->core = 0;
$view->api_version = '3.0-alpha1';
$view->disabled = FALSE; /* Edit this to true to make a default view disabled initially */

/* Display: Defaults */
$handler = $view->new_display('default', 'Defaults', 'default');
$handler->display->display_options['access']['type'] = 'none';
$handler->display->display_options['cache']['type'] = 'none';
$handler->display->display_options['query']['type'] = 'views_query';
$handler->display->display_options['exposed_form']['type'] = 'basic';
$handler->display->display_options['pager']['type'] = 'full';
$handler->display->display_options['style_plugin'] = 'default';
$handler->display->display_options['row_plugin'] = 'node';
$handler->display->display_options['row_options']['links'] = 1;
$handler->display->display_options['row_options']['comments'] = 0;
/* No results behavior: Global: Text area */
$handler->display->display_options['empty']['area']['id'] = 'area';
$handler->display->display_options['empty']['area']['table'] = 'views';
$handler->display->display_options['empty']['area']['field'] = 'area';
$handler->display->display_options['empty']['area']['empty'] = FALSE;
$handler->display->display_options['empty']['area']['content'] = 'There is no content in this group.';
/* Sort criterion: Content: Post date */
$handler->display->display_options['sorts']['created']['id'] = 'created';
$handler->display->display_options['sorts']['created']['table'] = 'node';
$handler->display->display_options['sorts']['created']['field'] = 'created';
$handler->display->display_options['sorts']['created']['order'] = 'DESC';
/* Contextual filter: Fields: Group Membership (group_audience:gid) */
$handler->display->display_options['arguments']['group_audience_gid']['id'] = 'group_audience_gid';
$handler->display->display_options['arguments']['group_audience_gid']['table'] = 'field_data_group_audience';
$handler->display->display_options['arguments']['group_audience_gid']['field'] = 'group_audience_gid';
$handler->display->display_options['arguments']['group_audience_gid']['default_action'] = 'default';
$handler->display->display_options['arguments']['group_audience_gid']['default_argument_type'] = 'fixed';
$handler->display->display_options['arguments']['group_audience_gid']['summary']['format'] = 'default_summary';
$handler->display->display_options['arguments']['group_audience_gid']['specify_validation'] = 1;
$handler->display->display_options['arguments']['group_audience_gid']['validate']['fail'] = 'empty';
$handler->display->display_options['arguments']['group_audience_gid']['break_phrase'] = 0;
$handler->display->display_options['arguments']['group_audience_gid']['not'] = 0;
/* Filter criterion: Content: Published */
$handler->display->display_options['filters']['status']['id'] = 'status';
$handler->display->display_options['filters']['status']['table'] = 'node';
$handler->display->display_options['filters']['status']['field'] = 'status';
$handler->display->display_options['filters']['status']['value'] = '1';

/* Display: Content pane */
$handler = $view->new_display('panel_pane', 'Content pane', 'panel_pane_1');
$handler->display->display_options['pane_title'] = 'OG nodes';
$handler->display->display_options['allow']['use_pager'] = 0;
$handler->display->display_options['allow']['items_per_page'] = 0;
$handler->display->display_options['allow']['offset'] = 0;
$handler->display->display_options['allow']['link_to_view'] = 0;
$handler->display->display_options['allow']['more_link'] = 0;
$handler->display->display_options['allow']['path_override'] = 0;
$handler->display->display_options['allow']['title_override'] = 'title_override';
$handler->display->display_options['allow']['exposed_form'] = 0;
$handler->display->display_options['allow']['fields_override'] = 0;
$handler->display->display_options['argument_input'] = array(
'group_audience_gid' => array(
'type' => 'context',
'context' => 'entity:group.gid',
'context_optional' => 0,
'panel' => '0',
'fixed' => '',
'label' => 'Fields: group_audience (group_audience) - gid',
),
);
$translatables['og_nodes'] = array(
t('Defaults'),
t('more'),
t('Apply'),
t('Reset'),
t('Sort by'),
t('Asc'),
t('Desc'),
t('Items per page'),
t('- All -'),
t('Offset'),
t('There is no content in this group.'),
t('All'),
t('Content pane'),
t('OG nodes'),
t('View panes'),
);

Thanks, dereine--that got rid of the error. I'm rather new at terminal and patches--here's what I got when I applied the patch:

File to patch: base.inc
patching file base.inc
patch unexpectedly ends in middle of line
Hunk #3 succeeded at 318 with fuzz 1.

not sure what fuzz 1 is, but I've tested a few things and it all seems to be ok--many thanks!

Same here. I updated to latest dev version, got the message, applied the patch and all is fine.