DB Error: MySQL server has gone away

Stack Trace:

File: /home/journals/public_html/lib/pkp/classes/session/SessionDAO.inc.php line 44
Function: DAO->retrieve("SELECT * FROM sessions WHERE session_id = ?", Array(1))

File: /home/journals/public_html/lib/pkp/classes/session/SessionManager.inc.php line 159
Function: SessionDAO->getSession("hd4ln6cutc13qnqbsomls1odu2")

File: (unknown) line (unknown)
Function: SessionManager->read("hd4ln6cutc13qnqbsomls1odu2")

File: /home/journals/public_html/lib/pkp/classes/session/SessionManager.inc.php line 59
Function: session_start()

File: /home/journals/public_html/lib/pkp/classes/session/SessionManager.inc.php line 120
Function: SessionManager->SessionManager(Object(SessionDAO), Object(Request))

File: /home/journals/public_html/classes/security/Validation.inc.php line 281
Function: SessionManager->getManager()

File: /home/journals/public_html/lib/pkp/classes/core/PKPPageRouter.inc.php line 66
Function: Validation->isLoggedIn()

File: /home/journals/public_html/lib/pkp/classes/core/Dispatcher.inc.php line 117
Function: PKPPageRouter->isCacheable(Object(Request))

File: /home/journals/public_html/lib/pkp/classes/core/PKPApplication.inc.php line 190
Function: Dispatcher->dispatch(Object(Request))

File: /home/journals/public_html/index.php line 64
Function: PKPApplication->execute()