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(Cannot access the database)
Backtrace:
#0 E:\xampp-1.8.3.4\htdocs\mediawiki\includes\libs\rdbms\loadbalancer\LoadBalancer.php(897): Database->reportConnectionError('Unknown error (...')
#1 E:\xampp-1.8.3.4\htdocs\mediawiki\includes\libs\rdbms\loadbalancer\LoadBalancer.php(572): LoadBalancer->reportConnectionError()
#2 E:\xampp-1.8.3.4\htdocs\mediawiki\includes\GlobalFunctions.php(3075): LoadBalancer->getConnection(-1, Array, false)
#3 E:\xampp-1.8.3.4\htdocs\mediawiki\includes\cache\MessageCache.php(444): wfGetDB(-1)
#4 E:\xampp-1.8.3.4\htdocs\mediawiki\includes\cache\MessageCache.php(403): MessageCache->loadFromDB('en', NULL)
#5 E:\xampp-1.8.3.4\htdocs\mediawiki\includes\cache\MessageCache.php(325): MessageCache->loadFromDBWithLock('en', Array, NULL)
#6 E:\xampp-1.8.3.4\htdocs\mediawiki\includes\cache\MessageCache.php(927): MessageCache->load('en')
#7 E:\xampp-1.8.3.4\htdocs\mediawiki\includes\cache\MessageCache.php(858): MessageCache->getMsgFromNamespace('Mainpage', 'en')
#8 E:\xampp-1.8.3.4\htdocs\mediawiki\includes\cache\MessageCache.php(826): MessageCache->getMessageForLang(Object(Language), 'mainpage', true, Array)
#9 E:\xampp-1.8.3.4\htdocs\mediawiki\includes\cache\MessageCache.php(767): MessageCache->getMessageFromFallbackChain(Object(Language), 'mainpage', true)
#10 E:\xampp-1.8.3.4\htdocs\mediawiki\includes\Message.php(1188): MessageCache->get('mainpage', true, Object(Language))
#11 E:\xampp-1.8.3.4\htdocs\mediawiki\includes\Message.php(802): Message->fetchMessage()
#12 E:\xampp-1.8.3.4\htdocs\mediawiki\includes\Message.php(914): Message->toString()
#13 E:\xampp-1.8.3.4\htdocs\mediawiki\extensions\RestrictAccessByCategoryAndGroup\RestrictAccessByCategoryAndGroup.php(28): Message->plain()
#14 [internal function]: restrictAccessByCategoryAndGroup(Object(Title), Object(User), 'read', '')
#15 E:\xampp-1.8.3.4\htdocs\mediawiki\includes\Hooks.php(195): call_user_func_array('restrictAccessB...', Array)
#16 E:\xampp-1.8.3.4\htdocs\mediawiki\includes\Title.php(2056): Hooks::run('userCan', Array)
#17 E:\xampp-1.8.3.4\htdocs\mediawiki\includes\Title.php(2498): Title->checkPermissionHooks('read', Object(User), Array, 'secure', false)
#18 E:\xampp-1.8.3.4\htdocs\mediawiki\includes\Title.php(1924): Title->getUserPermissionsErrorsInternal('read', Object(User), 'secure')
#19 E:\xampp-1.8.3.4\htdocs\mediawiki\includes\MediaWiki.php(202): Title->getUserPermissionsErrors('read', Object(User))
#20 E:\xampp-1.8.3.4\htdocs\mediawiki\includes\MediaWiki.php(851): MediaWiki->performRequest()
#21 E:\xampp-1.8.3.4\htdocs\mediawiki\includes\MediaWiki.php(512): MediaWiki->main()
#22 E:\xampp-1.8.3.4\htdocs\mediawiki\index.php(43): MediaWiki->run()
#23 {main}