[akismet] latest update, multisite unreachable

I am using the latest wordpress multisite version on https://www.mmo-game.eu/ and today updated akismet, but now the site is unreachable.

Front and Backend result in a “Briefly unavailable for scheduled maintenance. Check back in a minute.”

Can’t access anything and deleting akismet plugin did not really help.

Any suggestion?

https://www.ads-software.com/extend/plugins/akismet/