I solved the problem
1 - delete the folder of the plugin in this case mailbox.
2- go to phpmyadmin and explore your data base delete tables for the faulty plugin.
3- go to ow_system_plugins/base/components/console.php an delete this lines:
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{
OW::getPluginManager()->getPlugin('mailbox');
$mailsCount = MAILBOX_BOL_ConversationService::getInstance()->getNewInboxConversationCount(OW::getUser()->getId());
$links['mailbox'] = $router->urlForRoute('mailbox_default');
if ( $mailsCount > 0 )
{
$this->assign('new_mail', array('href' => $router->urlForRoute('mailbox_default'), 'count' => $mailsCount));
}
}
}
catch ( Exception $e )
{
try
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also delete this line:
'mailbox' => $language->text('base', 'console_item_label_mailbox'),
and ready your website is working again
retain all data except the data eliminated plugin