DB Error: Table './omniscient/sessions' is marked as crashed and should be repaired

Stack Trace:

File: /www/wwwroot/ojs.omniscient.sg/lib/pkp/classes/session/SessionDAO.inc.php line 37
Function: DAO->retrieve("SELECT * FROM sessions WHERE session_id = ?", Array(1))

File: /www/wwwroot/ojs.omniscient.sg/lib/pkp/classes/session/SessionManager.inc.php line 168
Function: SessionDAO->getSession("u8jv4fl3fm8ckvr99il52rljj3")

File: (unknown) line (unknown)
Function: SessionManager->read("u8jv4fl3fm8ckvr99il52rljj3")

File: /www/wwwroot/ojs.omniscient.sg/lib/pkp/classes/session/SessionManager.inc.php line 58
Function: session_start()

File: /www/wwwroot/ojs.omniscient.sg/lib/pkp/classes/session/SessionManager.inc.php line 129
Function: SessionManager->__construct(Object(SessionDAO), Object(Request))

File: /www/wwwroot/ojs.omniscient.sg/lib/pkp/classes/security/Validation.inc.php line 371
Function: SessionManager::getManager()

File: /www/wwwroot/ojs.omniscient.sg/lib/pkp/classes/core/PKPPageRouter.inc.php line 66
Function: Validation::isLoggedIn()

File: /www/wwwroot/ojs.omniscient.sg/lib/pkp/classes/core/Dispatcher.inc.php line 117
Function: PKPPageRouter->isCacheable(Object(Request))

File: /www/wwwroot/ojs.omniscient.sg/lib/pkp/classes/core/PKPApplication.inc.php line 252
Function: Dispatcher->dispatch(Object(Request))

File: /www/wwwroot/ojs.omniscient.sg/index.php line 67
Function: PKPApplication->execute()