Update abgebrochen Seite im Wartungsmodus

Hallo,
ich wollte direkt von 6.4.8.1 auf 6.4.9.0 updaten, die Seite ist im Wartungsmodus und ich komme nicht mehr ins Backend.
Was kann ich tun?
Datenbank Sicherung habe ich zurückgespielt.
jetzt kommt die Fehlermeldung:

Datenbank-Update durchführen
Error
Received an error message.
URL: unpack?offset=0&total=0
Message: Internal Server Error

Please try to fix this error and restart the update.
Response

{„code“:0,„message“:„The file files/backup/auto_update/dummy already exists and can not be overwritten.“,„file“:"/var/www/angmin/htdocs/shopwa6/vendor/shopware/recovery/Common/vendor
/knplabs/gaufrette/src/Gaufrette/Filesystem.php",„line“:100,„trace“:"#0 /var/www/angmin/htdocs/shopwa6/vendor/shopware/recovery/Update/src/Steps/UnpackStep.php(66): Gaufrette\Filesystem->write(‚files
/backup/au…‘, ‚dummyfile‘)\n#1 /var/www/angmin/htdocs/shopwa6/vendor/shopware/recovery/Update/src/Controller/BatchController.php(100): Shopware\Recovery\Update\Steps\UnpackStep->run(0, 0)\n#2
/var/www/angmin/htdocs/shopwa6/vendor/shopware/recovery/Update/src/app.php(97): Shopware\Recovery\Update\Controller\BatchController->unpack(Object(Slim\Http\Request), Object(Slim\Http\Response))
\n#3 [internal function]: Closure->{closure}(Object(Slim\Http\Request), Object(Slim\Http\Response), Array)\n#4 /var/www/angmin/htdocs/shopwa6/vendor/shopware/recovery/Common/vendor/slim/slim
/Slim/Handlers/Strategies/RequestResponse.php(40): call_user_func(Object(Closure), Object(Slim\Http\Request), Object(Slim\Http\Response), Array)\n#5 /var/www/angmin/htdocs/shopwa6/vendor/shopware
/recovery/Common/vendor/slim/slim/Slim/Route.php(281): Slim\Handlers\Strategies\RequestResponse->__invoke(Object(Closure), Object(Slim\Http\Request), Object(Slim\Http\Response), Array)\n#6 /var/www
/angmin/htdocs/shopwa6/vendor/shopware/recovery/Common/vendor/slim/slim/Slim/MiddlewareAwareTrait.php(117): Slim\Route->__invoke(Object(Slim\Http\Request), Object(Slim\Http\Response))\n#7 /var/www
/angmin/htdocs/shopwa6/vendor/shopware/recovery/Common/vendor/slim/slim/Slim/Route.php(268): Slim\Route->callMiddlewareStack(Object(Slim\Http\Request), Object(Slim\Http\Response))\n#8 /var/www/angmin
/htdocs/shopwa6/vendor/shopware/recovery/Common/vendor/slim/slim/Slim/App.php(503): Slim\Route->run(Object(Slim\Http\Request), Object(Slim\Http\Response))\n#9 /var/www/angmin/htdocs/shopwa6/vendor
/shopware/recovery/Update/src/app.php(72): Slim\App->__invoke(Object(Slim\Http\Request), Object(Slim\Http\Response))\n#10 [internal function]: Closure->{closure}(Object(Slim\Http\Request), Object(Slim\Http\
Response), Object(Slim\App))\n#11 /var/www/angmin/htdocs/shopwa6/vendor/shopware/recovery/Common/vendor/slim/slim/Slim/DeferredCallable.php(57): call_user_func_array(Object(Closure), Array)
\n#12 [internal function]: Slim\DeferredCallable->__invoke(Object(Slim\Http\Request), Object(Slim\Http\Response), Object(Slim\App))\n#13 /var/www/angmin/htdocs/shopwa6/vendor/shopware/recovery
/Common/vendor/slim/slim/Slim/MiddlewareAwareTrait.php(70): call_user_func(Object(Slim\DeferredCallable), Object(Slim\Http\Request), Object(Slim\Http\Response), Object(Slim\App))\n#14 /var/www/angmin
/htdocs/shopwa6/vendor/shopware/recovery/Common/vendor/slim/slim/Slim/MiddlewareAwareTrait.php(117): Slim\App->Slim\{closure}(Object(Slim\Http\Request), Object(Slim\Http\Response))\n#15 /var/www
/angmin/htdocs/shopwa6/vendor/shopware/recovery/Common/vendor/slim/slim/Slim/App.php(392): Slim\App->callMiddlewareStack(Object(Slim\Http\Request), Object(Slim\Http\Response))\n#16 /var/www/angmin
/htdocs/shopwa6/vendor/shopware/recovery/Common/vendor/slim/slim/Slim/App.php(297): Slim\App->process(Object(Slim\Http\Request), Object(Slim\Http\Response))\n#17 /var/www/angmin/htdocs/shopwa6/vendor
/shopware/recovery/Update/index.php(39): Slim\App->run()\n#18 /var/www/angmin/htdocs/shopwa6/public/recovery/update/index.php(6): require_once(’/var/www/angmin…’)\n#19 {main}"}

Shopware erkennt, dass schon ein Update-Versuch unternommen wurde und blockiert das Update.

Hier im Forum gibt es zahlreiche Beiträge dazu. Vermutlich hilft das Suchwort dummy.

Ansonsten, ohne es sicher zu wissen, ich glaube es muss einfach die dummy-Datei gelöscht werden. Lese aber lieber noch einmal nach!