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

SELECT data
  FROM piwigo_sessions
  WHERE id = '22E4s3rvbr76slr8alksovbgmtm714'
; in /home/sarah/public_html/piwigo/include/dblayer/functions_mysqli.inc.php on line 845

Call Stack:
    0.0001     239824   1. {main}() /home/sarah/public_html/piwigo/index.php:0
    0.0001     240760   2. include_once('/home/sarah/public_html/piwigo/include/common.inc.php') /home/sarah/public_html/piwigo/index.php:26
    0.0037     603336   3. session_start() /home/sarah/public_html/piwigo/include/common.inc.php:156
    0.0037     604096   4. pwg_session_read() /home/sarah/public_html/piwigo/include/common.inc.php:156
    0.0037     604288   5. pwg_query() /home/sarah/public_html/piwigo/include/functions_session.inc.php:147
    0.0040     604512   6. my_error() /home/sarah/public_html/piwigo/include/dblayer/functions_mysqli.inc.php:147
    0.0040     604856   7. trigger_error() /home/sarah/public_html/piwigo/include/dblayer/functions_mysqli.inc.php:845

Fatal error: Call to a member function fetch_assoc() on boolean in /home/sarah/public_html/piwigo/include/dblayer/functions_mysqli.inc.php on line 226 Call Stack: 0.0001 239824 1. {main}() /home/sarah/public_html/piwigo/index.php:0 0.0001 240760 2. include_once('/home/sarah/public_html/piwigo/include/common.inc.php') /home/sarah/public_html/piwigo/index.php:26 0.0037 603336 3. session_start() /home/sarah/public_html/piwigo/include/common.inc.php:156 0.0037 604096 4. pwg_session_read() /home/sarah/public_html/piwigo/include/common.inc.php:156 0.0042 604464 5. pwg_db_fetch_assoc() /home/sarah/public_html/piwigo/include/functions_session.inc.php:148
Warning: [mysql error 145] Table './sarah/piwigo_sessions' is marked as crashed and should be repaired

REPLACE INTO piwigo_sessions
  (id,data,expiration)
  VALUES('22E4s3rvbr76slr8alksovbgmtm714','',now())
; in /home/sarah/public_html/piwigo/include/dblayer/functions_mysqli.inc.php on line 845

Call Stack:
    0.0001     239824   1. {main}() /home/sarah/public_html/piwigo/index.php:0
    0.0001     240760   2. include_once('/home/sarah/public_html/piwigo/include/common.inc.php') /home/sarah/public_html/piwigo/index.php:26
    0.0037     603336   3. session_start() /home/sarah/public_html/piwigo/include/common.inc.php:156
    0.0037     604096   4. pwg_session_read() /home/sarah/public_html/piwigo/include/common.inc.php:156
    0.0042     604464   5. pwg_db_fetch_assoc() /home/sarah/public_html/piwigo/include/functions_session.inc.php:148
    0.0043     604608   6. session_write_close() /home/sarah/public_html/piwigo/include/functions_session.inc.php:0
    0.0043     604912   7. pwg_session_write() /home/sarah/public_html/piwigo/include/functions_session.inc.php:0
    0.0043     605120   8. pwg_query() /home/sarah/public_html/piwigo/include/functions_session.inc.php:169
    0.0045     605216   9. my_error() /home/sarah/public_html/piwigo/include/dblayer/functions_mysqli.inc.php:147
    0.0046     605584  10. trigger_error() /home/sarah/public_html/piwigo/include/dblayer/functions_mysqli.inc.php:845