Cannot access ADMIN/Back Office - errors thrown

[RescueDog]

Thank you in advance for any help. I haven't been in the BO for some time - thankfully everything has been running smoothly so I didn't want to jinx it. Well, I logged in last night - checked a few messages, accessed the modules page and exited. This evening I cannot get the BO login page to load.
 

Warning: simplexml_load_file(): /home/topaward/public_html/knightsshop/prestaxxxxx/config/xml/default_country_modules_list.xml:1: parser error : Document is empty in /home/topaward/public_html/knightsshop/prestaxxxxx/classes/controller/AdminController.phpon line 1542

Warning: simplexml_load_file(): in/home/topaward/public_html/knightsshop/prestaxxxxx/classes/controller/AdminController.php on line 1542

Warning: simplexml_load_file(): ^ in/home/topaward/public_html/knightsshop/prestaxxxxx/classes/controller/AdminController.php on line 1542

Warning: simplexml_load_file(): /home/topaward/public_html/knightsshop/prestaxxxxx/config/xml/default_country_modules_list.xml:1: parser error : Start tag expected, '<' not found in/home/topaward/public_html/knightsshop/prestaxxxxx/classes/controller/AdminController.php on line 1542

Warning: simplexml_load_file(): in/home/topaward/public_html/knightsshop/prestaxxxxx/classes/controller/AdminController.php on line 1542

Warning: simplexml_load_file(): ^ in/home/topaward/public_html/knightsshop/prestaxxxxx/classes/controller/AdminController.php on line 1542

Warning: Invalid argument supplied for foreach() in/home/topaward/public_html/knightsshop/prestaxxxxx/classes/controller/AdminController.php on line 1544

Warning: Error while sending QUERY packet. PID=48575 in/home/topaward/public_html/knightsshop/prestaxxxxx/classes/db/DbPDO.php on line 91

Warning: Cannot modify header information - headers already sent by (output started at /home/topaward/public_html/knightsshop/prestaxxxxx/classes/controller/AdminController.php:1542) in/home/topaward/public_html/knightsshop/prestaxxxxx/classes/exception/PrestaShopException.php on line 37
[PrestaShopDatabaseException]MySQL server has gone away

            SELECT module
            FROM ps_tab_module_preference
            WHERE `id_tab` = 1
            AND `id_employee` = 1
at line 613 in file classes/db/Db.php
607.             WebserviceRequest::getInstance()->setError(500, '[SQL Error] '.$this->getMsgError().'. From '.(isset($dbg[3]['class']) ? $dbg[3]['class'] : '').'->'.$dbg[3]['function'].'() Query was : '.$sql, 97);
608.         }
609.         else if (_PS_DEBUG_SQL_ && $errno && !defined('PS_INSTALLATION_IN_PROGRESS'))
610.         {
611.             if ($sql)
612.                 throw new PrestaShopDatabaseException($this->getMsgError().'<br /><br /><pre>'.$sql.'</pre>');
613.             throw new PrestaShopDatabaseException($this->getMsgError());
614.         }
615.     }
616.
617.     /**

DbCore->displayError - [line 313 - classes/db/Db.php] - [1 Arguments]
DbCore->query - [line 488 - classes/db/Db.php] - [1 Arguments]
DbCore->executeS - [line 528 - classes/Tab.php] - [1 Arguments]
TabCore::getTabModulesList - [line 1520 - classes/controller/AdminController.php] - [1 Arguments]
AdminControllerCore->initTabModuleList - [line 1478 - classes/controller/AdminController.php] - [0 Argument]
AdminControllerCore->initContent - [line 662 - controllers/admin/AdminHomeController.php] - [0 Argument]
AdminHomeControllerCore->initContent - [line 167 - classes/controller/Controller.php] - [0 Argument]
ControllerCore->run - [line 348 - classes/Dispatcher.php] - [0 Argument]
DispatcherCore->dispatch - [line 50 - adminkoc/index.php] - [0 Argument]

running PS 1.5.1  

~Jo

[rocky]

There must have been an error downloading config/xml/default_country_modules_list.xml and the file is incomplete. Try deleting the file and it should be re-downloaded automatically.

[RescueDog]

Thank you for the guidance. This afternoon, my first chance to look at it, the BO dashboard loads. I haven't touched a thing. So frustrating.

Would it be anyone's opinion that this was caused by the host making changes in a supposed 'production' environment? 

Thanks again.

~Jo

[rocky]

It's possible, but it's hard to say what caused it with any certainty. Hopefully, it was a rare connection problem between your server and PrestaShop's server.