I am working in my website , and suddenly I got a strange error in the main page and another error when I enter to any of the fields !!!
My website : www.al-wahah.com/

The first Error is :
Got error 28 from storage engine SQL=SELECT a.id, a.title, a.alias, a.introtext, a.fulltext, a.checked_out, a.checked_out_time, a.catid, a.created, a.created_by, a.created_by_alias, CASE WHEN a.modified = '0000-00-00 00:00:00' THEN a.created ELSE a.modified END as modified, a.modified_by, uam.name as modified_by_name,CASE WHEN a.publish_up = '0000-00-00 00:00:00' THEN a.created ELSE a.publish_up END as publish_up,a.publish_down, a.images, a.urls, a.attribs, a.metadata, a.metakey, a.metadesc, a.access, a.hits, a.xreference, a.featured, a.language, LENGTH(a.fulltext) AS readmore,CASE WHEN badcats.id is not null THEN 0 ELSE a.state END AS state,c.title AS category_title, c.path AS category_route, c.access AS category_access, c.alias AS category_alias,CASE WHEN a.created_by_alias > ' ' THEN a.created_by_alias ELSE ua.name END AS author,ua.email AS author_email,parent.title as parent_title, parent.id as parent_id, parent.path as parent_route, parent.alias as parent_alias,ROUND(v.rating_sum / v.rating_count, 0) AS rating, v.rating_count as rating_count,c.published, CASE WHEN badcats.id is null THEN c.published ELSE 0 END AS parents_published FROM kzpr_content AS a LEFT JOIN kzpr_categories AS c ON c.id = a.catid LEFT JOIN kzpr_users AS ua ON ua.id = a.created_by LEFT JOIN kzpr_users AS uam ON uam.id = a.modified_by LEFT JOIN kzpr_categories as parent ON parent.id = c.parent_id LEFT JOIN kzpr_content_rating AS v ON a.id = v.content_id LEFT OUTER JOIN (SELECT cat.id as id FROM kzpr_categories AS cat JOIN kzpr_categories AS parent ON cat.lft BETWEEN parent.lft AND parent.rgt WHERE parent.extension = 'com_content' AND parent.published != 1 GROUP BY cat.id ) AS badcats ON badcats.id = c.id INNER JOIN kzpr_content_frontpage AS fp ON fp.content_id = a.id WHERE a.access IN (1,1,5) AND c.access IN (1,1,5) AND CASE WHEN badcats.id is null THEN a.state ELSE 0 END = 1 AND (a.publish_up = '0000-00-00 00:00:00' OR a.publish_up <= '2015-02-07 13:57:43') AND (a.publish_down = '0000-00-00 00:00:00' OR a.publish_down >= '2015-02-07 13:57:43') ORDER BY c.lft, CASE WHEN a.publish_up = '0000-00-00 00:00:00' THEN a.created ELSE a.publish_up END DESC , a.created DESC LIMIT 0, 9

The second Error is :
Got error 28 from storage engine SQL=SELECT adext.*, a.*, p.name as parent, p.id as parentid, c.name as cat, c.id as catid,u.username as user,u.name as fullname FROM kzpr_adsmanager_ads as a LEFT JOIN kzpr_paidsystem_ads as adext ON a.id = adext.id INNER JOIN kzpr_adsmanager_adcat as adcat ON adcat.adid = a.id LEFT JOIN kzpr_users as u ON a.userid = u.id INNER JOIN kzpr_adsmanager_categories as c ON adcat.catid = c.id LEFT JOIN kzpr_adsmanager_categories as p ON c.parent = p.id WHERE a.published = 1 AND c.published = TRUE AND c.id IN (3) AND c.id IN (4,3,5) AND c.id IN (2,18,1,9,11,3,4,5,6,7,8,15,16,17) GROUP BY a.id ORDER BY adext.top DESC, a.date_created DESC ,a.id DESC LIMIT 0, 20