[ZgaxM4bqt51vXAWbz5sixwAAHAs] /index.php?title=Spezial:Suche&search=Wikipadmin UnexpectedValueException: Invalid server index index #DB_SLAVE

Backtrace:

from /www/htdocs/w00a8ef1/passagierrechte.org/includes/libs/rdbms/loadbalancer/LoadBalancer.php(513)
#0 /www/htdocs/w00a8ef1/passagierrechte.org/includes/libs/rdbms/loadbalancer/LoadBalancer.php(958): Wikimedia\Rdbms\LoadBalancer->getConnectionIndex(string, array, string)
#1 /www/htdocs/w00a8ef1/passagierrechte.org/includes/libs/rdbms/loadbalancer/LoadBalancer.php(1126): Wikimedia\Rdbms\LoadBalancer->getConnection(string, array, string, integer)
#2 /www/htdocs/w00a8ef1/passagierrechte.org/includes/GlobalFunctions.php(2462): Wikimedia\Rdbms\LoadBalancer->getMaintenanceConnectionRef(string, array, string)
#3 /www/htdocs/w00a8ef1/passagierrechte.org/extensions/KeepSearches/KeepSearches.php(51): wfGetDB(string)
#4 /www/htdocs/w00a8ef1/passagierrechte.org/includes/Setup.php(838): wfKeepSearchesExtension()
#5 /www/htdocs/w00a8ef1/passagierrechte.org/includes/WebStart.php(87): require_once(string)
#6 /www/htdocs/w00a8ef1/passagierrechte.org/index.php(44): require(string)
#7 {main}