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

SELECT data
  FROM piwigo_sessions
  WHERE id = '22E7a9uu63qulg7qa9ebvkgtsirok6'
; in /home/sarah/public_html/piwigo/include/dblayer/functions_mysqli.inc.php on line 845

Call Stack:
    0.0000     241088   1. {main}() /home/sarah/public_html/piwigo/index.php:0
    0.0001     242024   2. include_once('/home/sarah/public_html/piwigo/include/common.inc.php') /home/sarah/public_html/piwigo/index.php:26
    0.0020     604864   3. session_start() /home/sarah/public_html/piwigo/include/common.inc.php:156
    0.0020     605624   4. pwg_session_read() /home/sarah/public_html/piwigo/include/common.inc.php:156
    0.0020     605816   5. pwg_query() /home/sarah/public_html/piwigo/include/functions_session.inc.php:147
    0.0022     606040   6. my_error() /home/sarah/public_html/piwigo/include/dblayer/functions_mysqli.inc.php:147
    0.0022     606384   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: 0.0000 241088 1. {main}() /home/sarah/public_html/piwigo/index.php:0 0.0001 242024 2. include_once('/home/sarah/public_html/piwigo/include/common.inc.php') /home/sarah/public_html/piwigo/index.php:26 0.0020 604864 3. session_start() /home/sarah/public_html/piwigo/include/common.inc.php:156 0.0020 605624 4. pwg_session_read() /home/sarah/public_html/piwigo/include/common.inc.php:156 0.0023 605992 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('22E7a9uu63qulg7qa9ebvkgtsirok6','',now())
; in /home/sarah/public_html/piwigo/include/dblayer/functions_mysqli.inc.php on line 845

Call Stack:
    0.0000     241088   1. {main}() /home/sarah/public_html/piwigo/index.php:0
    0.0001     242024   2. include_once('/home/sarah/public_html/piwigo/include/common.inc.php') /home/sarah/public_html/piwigo/index.php:26
    0.0020     604864   3. session_start() /home/sarah/public_html/piwigo/include/common.inc.php:156
    0.0020     605624   4. pwg_session_read() /home/sarah/public_html/piwigo/include/common.inc.php:156
    0.0023     605992   5. pwg_db_fetch_assoc() /home/sarah/public_html/piwigo/include/functions_session.inc.php:148
    0.0024     606136   6. session_write_close() /home/sarah/public_html/piwigo/include/functions_session.inc.php:0
    0.0024     606440   7. pwg_session_write() /home/sarah/public_html/piwigo/include/functions_session.inc.php:0
    0.0024     606648   8. pwg_query() /home/sarah/public_html/piwigo/include/functions_session.inc.php:169
    0.0025     606744   9. my_error() /home/sarah/public_html/piwigo/include/dblayer/functions_mysqli.inc.php:147
    0.0025     607112  10. trigger_error() /home/sarah/public_html/piwigo/include/dblayer/functions_mysqli.inc.php:845