Internal Server Error

[14ba4a81f1404b4ed2325364] /wiki/api.php?action=feedcontributions&user=Tamaradamberg&feedformat=atom Wikimedia\Rdbms\DBConnectionError from line 1195 of /var/www/html/wiki/includes/libs/rdbms/loadbalancer/LoadBalancer.php: Cannot access the database: Unknown error (localhost)
Backtrace:
#0 /var/www/html/wiki/includes/libs/rdbms/loadbalancer/LoadBalancer.php(769): Wikimedia\Rdbms\LoadBalancer->reportConnectionError()
#1 /var/www/html/wiki/includes/GlobalFunctions.php(2694): Wikimedia\Rdbms\LoadBalancer->getConnection(integer, array, boolean)
#2 /var/www/html/wiki/includes/cache/localisation/LCStoreDB.php(54): wfGetDB(integer)
#3 /var/www/html/wiki/includes/cache/localisation/LocalisationCache.php(410): LCStoreDB->get(string, string)
#4 /var/www/html/wiki/includes/cache/localisation/LocalisationCache.php(456): LocalisationCache->isExpired(string)
#5 /var/www/html/wiki/includes/cache/localisation/LocalisationCache.php(375): LocalisationCache->initLanguage(string)
#6 /var/www/html/wiki/includes/cache/localisation/LocalisationCache.php(294): LocalisationCache->loadSubitem(string, string, string)
#7 /var/www/html/wiki/languages/Language.php(2643): LocalisationCache->getSubitem(string, string, string)
#8 /var/www/html/wiki/includes/cache/MessageCache.php(970): Language->getMessage(string)
#9 /var/www/html/wiki/includes/cache/MessageCache.php(928): MessageCache->getMessageForLang(LanguageEn, string, boolean, array)
#10 /var/www/html/wiki/includes/cache/MessageCache.php(870): MessageCache->getMessageFromFallbackChain(LanguageEn, string, boolean)
#11 /var/www/html/wiki/includes/Message.php(1299): MessageCache->get(string, boolean, LanguageEn)
#12 /var/www/html/wiki/includes/Message.php(851): Message->fetchMessage()
#13 /var/www/html/wiki/includes/Message.php(943): Message->toString(string)
#14 /var/www/html/wiki/includes/api/ApiErrorFormatter.php(433): Message->text()
#15 /var/www/html/wiki/includes/api/ApiErrorFormatter.php(128): ApiErrorFormatter_BackCompat->addWarningOrError(string, NULL, ApiMessage)
#16 /var/www/html/wiki/includes/api/ApiMain.php(1081): ApiErrorFormatter->addError(NULL, ApiMessage)
#17 /var/www/html/wiki/includes/api/ApiMain.php(581): ApiMain->substituteResultWithError(Wikimedia\Rdbms\DBConnectionError)
#18 /var/www/html/wiki/includes/api/ApiMain.php(538): ApiMain->handleException(Wikimedia\Rdbms\DBConnectionError)
#19 /var/www/html/wiki/includes/api/ApiMain.php(502): ApiMain->executeActionWithErrorHandling()
#20 /var/www/html/wiki/api.php(87): ApiMain->execute()
#21 {main}