Try waiting a few minutes and reloading.
(Cannot access the database)
Backtrace:
#0 /home/ppu/public_html/KOER/en/includes/libs/rdbms/loadbalancer/LoadBalancer.php(937): Wikimedia\Rdbms\LoadBalancer->reportConnectionError() #1 /home/ppu/public_html/KOER/en/includes/libs/rdbms/loadbalancer/LoadBalancer.php(904): Wikimedia\Rdbms\LoadBalancer->getServerConnection(0, 'ppu_enkoerwiki1...', 0) #2 /home/ppu/public_html/KOER/en/extensions/BlueSpiceFoundation/vendor/mwstake/mediawiki-component-datastore/src/DatabaseReader.php(23): Wikimedia\Rdbms\LoadBalancer->getConnection(-1) #3 /home/ppu/public_html/KOER/en/extensions/BlueSpiceFoundation/src/Data/Settings/Reader.php(15): MWStake\MediaWiki\Component\DataStore\DatabaseReader->__construct(Object(Wikimedia\Rdbms\LoadBalancer), Object(BlueSpice\Context), Object(BlueSpice\Config)) #4 /home/ppu/public_html/KOER/en/extensions/BlueSpiceFoundation/src/Data/Settings/Store.php(31): BlueSpice\Data\Settings\Reader->__construct(Object(Wikimedia\Rdbms\LoadBalancer), Object(BlueSpice\Context)) #5 /home/ppu/public_html/KOER/en/extensions/BlueSpiceFoundation/src/Config.php(60): BlueSpice\Data\Settings\Store->getReader() #6 /home/ppu/public_html/KOER/en/extensions/BlueSpiceFoundation/src/Config.php(26): BlueSpice\Config->makeDatabaseConfig() #7 /home/ppu/public_html/KOER/en/extensions/BlueSpiceFoundation/src/Config.php(41): BlueSpice\Config->__construct() #8 /home/ppu/public_html/KOER/en/includes/config/ConfigFactory.php(143): BlueSpice\Config::newInstance(Object(ConfigFactory)) #9 /home/ppu/public_html/KOER/en/extensions/BlueSpiceFoundation/src/Foundation.php(121): ConfigFactory->makeConfig('bsg') #10 /home/ppu/public_html/KOER/en/extensions/BlueSpiceFoundation/src/Foundation.php(59): BlueSpice\Foundation->initialize() #11 /home/ppu/public_html/KOER/en/includes/Setup.php(806): BlueSpice\Foundation::BlueSpice\{closure}() #12 /home/ppu/public_html/KOER/en/includes/WebStart.php(89): require_once('/home/ppu/publi...') #13 /home/ppu/public_html/KOER/en/index.php(44): require('/home/ppu/publi...') #14 {main}