Yes, I did that and got the site back up. Thanks.
If it works like other sites, your members details should still be in the database and it should be just a matter of getting your config filled with the right info to connect to the database.
I am waiting to get my 500 error sorted then I am going to attempt a migration which will hilight the files you will need to ediyt to get your site working. I would post this as a seperate issue as it is now not 500 error related but a loss of dbase connection.
I know they do take a while to get back but I blame timezones etc for that along with workload.
Try looking in the config.php where addenster told us to edit and change to debug on, in there are your dbase connections, The name, server, username and password along with other info there help to connect to the database.
This is the content of a generic config.php file
define('OW_URL_HOME', '
http://siteurl.com');
define('OW_DB_HOST', 'servername');
define('OW_DB_USER', 'username');
define('OW_DB_PASSWORD', 'password');
define('OW_DB_NAME', 'dbname');
define('OW_DB_PREFIX', 'ow_');
define('OW_DIR_USERFILES', OW_DIR_ROOT.'ow_userfiles'.DS);
define('OW_DIR_STATIC', OW_DIR_ROOT.'ow_static'.DS);
define('OW_URL_STATIC', OW_URL_HOME.'ow_static/');
define('OW_URL_USERFILES', OW_URL_HOME.'ow_userfiles/');
define('OW_DIR_PLUGINFILES', OW_DIR_ROOT.'ow_pluginfiles/');
define('OW_DEBUG_MODE', false);
define('OW_DEV_MODE', true);
define('OW_INSTALL_PLUGINS', false);
define('OW_PASSWORD_SALT', 'oxwall_salt_SK750');
define('OW_PROFILER_ENABLE', false);
define('OW_DIR_CORE', OW_DIR_ROOT.'ow_core'.DS);
define('OW_DIR_INC', OW_DIR_ROOT.'ow_includes'.DS);
define('OW_DIR_LIB', OW_DIR_ROOT.'ow_libraries'.DS);
define('OW_DIR_UTIL', OW_DIR_ROOT.'ow_utilities'.DS);
define('OW_DIR_PLUGIN', OW_DIR_ROOT.'ow_plugins'.DS);
define('OW_DIR_THEME', OW_DIR_ROOT.'ow_themes'.DS);
define('OW_DIR_SYSTEM_PLUGIN', OW_DIR_ROOT.'ow_system_plugins'.DS);
define('OW_DIR_SMARTY', OW_DIR_ROOT.'ow_smarty'.DS);
define('OW_USE_CLOUDFILES', false);
Good luck... Wait for support to confirm this if you can...