Fatal error: Class 'JModelLegacy'

Hi when i try to use the component the browser show me:

Fatal error: Class 'JModelLegacy' not found in /web/htdocs/www.friulisitiweb.it/home/vienna2/administrator/components/com_solidres/helpers/helper.php on line 13

I have the latest version of joomla

Joomla! 2.5.4 Stable [ Ember ] 2-April-2012 14:00 GMT

done but the new error is

SQL=SELECT a.*,cat.title AS category_name,COUNT(rt.id) AS number_of_roomtype,cou.name AS country_name,uc.name AS editor,ag.title AS access_level FROM `mclwe_sr_reservation_assets` AS a LEFT JOIN `mclwe_categories` AS cat ON cat.id = a.category_id LEFT JOIN `mclwe_sr_room_types` AS rt ON rt.reservation_asset_id = a.id LEFT JOIN `mclwe_sr_countries` AS cou ON cou.id = a.country_id LEFT JOIN `mclwe_users` AS uc ON uc.id=a.checked_out LEFT JOIN `mclwe_viewlevels` AS ag ON ag.id = a.access WHERE (a.state IN (0, 1)) GROUP BY cat.title,cou.name,uc.name,ag.title,a.id ORDER BY a.name asc LIMIT 0, 20 SQL=SELECT a.*,cat.title AS category_name,COUNT(rt.id) AS number_of_roomtype,cou.name AS country_name,uc.name AS editor,ag.title AS access_level FROM `mclwe_sr_reservation_assets` AS a LEFT JOIN `mclwe_categories` AS cat ON cat.id = a.category_id LEFT JOIN `mclwe_sr_room_types` AS rt ON rt.reservation_asset_id = a.id LEFT JOIN `mclwe_sr_countries` AS cou ON cou.id = a.country_id LEFT JOIN `mclwe_users` AS uc ON uc.id=a.checked_out LEFT JOIN `mclwe_viewlevels` AS ag ON ag.id = a.access WHERE (a.state IN (0, 1)) GROUP BY cat.title,cou.name,uc.name,ag.title,a.id ORDER BY a.name asc