Error message

• Warning: Cannot modify header information - headers already sent by (output started at /users/var/www/drupal-7.22/includes/common.inc:2748) in drupal_send_headers() (line 1233 of /users/var/www/drupal-7.22/includes/bootstrap.inc).
• PDOException: SQLSTATE[HY000]: General error: 144 Table './drupal7/watchdog' is marked as crashed and last (automatic?) repair failed: INSERT INTO {watchdog} (uid, type, message, variables, severity, link, location, referer, hostname, timestamp) VALUES (:db_insert_placeholder_0, :db_insert_placeholder_1, :db_insert_placeholder_2, :db_insert_placeholder_3, :db_insert_placeholder_4, :db_insert_placeholder_5, :db_insert_placeholder_6, :db_insert_placeholder_7, :db_insert_placeholder_8, :db_insert_placeholder_9); Array ( [:db_insert_placeholder_0] => 0 [:db_insert_placeholder_1] => cron [:db_insert_placeholder_2] => %type: !message in %function (line %line of %file). [:db_insert_placeholder_3] => a:6:{s:5:"%type";s:12:"PDOException";s:8:"!message";s:218:"SQLSTATE[HY000]: General error: 144 Table './drupal7/watchdog' is marked as crashed and last (automatic?) repair failed: SELECT w.wid AS wid FROM {watchdog} w ORDER BY wid DESC LIMIT 1 OFFSET 999; Array ( ) ";s:9:"%function";s:12:"dblog_cron()";s:5:"%file";s:53:"/users/var/www/drupal-7.22/modules/dblog/dblog.module";s:5:"%line";i:113;s:14:"severity_level";i:3;} [:db_insert_placeholder_4] => 3 [:db_insert_placeholder_5] => [:db_insert_placeholder_6] => http://web.ffn.ub.es/node/2?id=conrad [:db_insert_placeholder_7] => [:db_insert_placeholder_8] => 44.212.94.18 [:db_insert_placeholder_9] => 1702004832 ) in dblog_watchdog() (line 160 of /users/var/www/drupal-7.22/modules/dblog/dblog.module).