Warning: [mysql error 145] Table './weatherd_piwi/piwigo_sessions' is marked as crashed and should be repaired

SELECT data
  FROM piwigo_sessions
  WHERE id = '12CFh8os8ld7uu9ukvfdkrk0fv1cu6'
; in /var/www/vhosts/weatherdata.gr/httpdocs/piwigo/include/dblayer/functions_mysqli.inc.php on line 845
Warning: [mysql error 145] Table './weatherd_piwi/piwigo_whois_online' is marked as crashed and should be repaired
SELECT * FROM piwigo_whois_online; in /var/www/vhosts/weatherdata.gr/httpdocs/piwigo/include/dblayer/functions_mysqli.inc.php on line 845
Fatal error: Call to a member function fetch_assoc() on a non-object in /var/www/vhosts/weatherdata.gr/httpdocs/piwigo/include/dblayer/functions_mysqli.inc.php on line 226
Warning: [mysql error 145] Table './weatherd_piwi/piwigo_sessions' is marked as crashed and should be repaired

REPLACE INTO piwigo_sessions
  (id,data,expiration)
  VALUES('12CFh8os8ld7uu9ukvfdkrk0fv1cu6','pwg_device|s:7:\"desktop\";pwg_mobile_theme|b:0;pwg_lang_switch|s:5:\"is_IS\";',now())
; in /var/www/vhosts/weatherdata.gr/httpdocs/piwigo/include/dblayer/functions_mysqli.inc.php on line 845