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

SELECT data
  FROM piwigo_sessions
  WHERE id = '369D7pqd0kfdu0cbe2sb7edsv8jnj1'
; in /home/sarah/public_html/piwigo/include/dblayer/functions_mysqli.inc.php on line 845

Call Stack:
    0.0000     240624   1. {main}() /home/sarah/public_html/piwigo/index.php:0
    0.0001     241560   2. include_once('/home/sarah/public_html/piwigo/include/common.inc.php') /home/sarah/public_html/piwigo/index.php:26
    0.0033     604160   3. session_start() /home/sarah/public_html/piwigo/include/common.inc.php:156
    0.0033     604920   4. pwg_session_read() /home/sarah/public_html/piwigo/include/common.inc.php:156
    0.0033     605112   5. pwg_query() /home/sarah/public_html/piwigo/include/functions_session.inc.php:147
    0.0036     605336   6. my_error() /home/sarah/public_html/piwigo/include/dblayer/functions_mysqli.inc.php:147
    0.0036     605680   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 240624 1. {main}() /home/sarah/public_html/piwigo/index.php:0 0.0001 241560 2. include_once('/home/sarah/public_html/piwigo/include/common.inc.php') /home/sarah/public_html/piwigo/index.php:26 0.0033 604160 3. session_start() /home/sarah/public_html/piwigo/include/common.inc.php:156 0.0033 604920 4. pwg_session_read() /home/sarah/public_html/piwigo/include/common.inc.php:156 0.0038 605288 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('369D7pqd0kfdu0cbe2sb7edsv8jnj1','',now())
; in /home/sarah/public_html/piwigo/include/dblayer/functions_mysqli.inc.php on line 845

Call Stack:
    0.0000     240624   1. {main}() /home/sarah/public_html/piwigo/index.php:0
    0.0001     241560   2. include_once('/home/sarah/public_html/piwigo/include/common.inc.php') /home/sarah/public_html/piwigo/index.php:26
    0.0033     604160   3. session_start() /home/sarah/public_html/piwigo/include/common.inc.php:156
    0.0033     604920   4. pwg_session_read() /home/sarah/public_html/piwigo/include/common.inc.php:156
    0.0038     605288   5. pwg_db_fetch_assoc() /home/sarah/public_html/piwigo/include/functions_session.inc.php:148
    0.0039     605432   6. session_write_close() /home/sarah/public_html/piwigo/include/functions_session.inc.php:0
    0.0039     605736   7. pwg_session_write() /home/sarah/public_html/piwigo/include/functions_session.inc.php:0
    0.0039     605944   8. pwg_query() /home/sarah/public_html/piwigo/include/functions_session.inc.php:169
    0.0041     606040   9. my_error() /home/sarah/public_html/piwigo/include/dblayer/functions_mysqli.inc.php:147
    0.0041     606408  10. trigger_error() /home/sarah/public_html/piwigo/include/dblayer/functions_mysqli.inc.php:845