Update 20.0.8 > 20.0.9 / Error Verifying Integrity

Hi and Hello,

does anyone has an idea, what could be wrong: 5 Instances of Nextcloud have the same problem while updating 20.0.8 to 20.0.9. It stops in the Step " Verifying integrity" using the web-based update. All other errors are solved, but there is no information concerning the reason.

What is to do? PHP is 7.4, > apc.enable_cli=1 is set, memcache not
Bildschirmfoto 2021-04-29 um 10.23.05

Thanks a lot!
Best regards!

Is there any idea, what I can do?