Internal Server Error Nextcloudpi

Hi everyone I might messed up the permissions the last thing I did was using Sudo Su to copy some files direct into the /var/www/nextcloud/files/USER/ folder. After a while the respberry Pi 4 froze and I had to restart by unplunging it. Now I get an ā€œInternal Server Errorā€ when trying to reache the server in the Browser. Also a Reboot isnt posssible anymore I get the Error ā€œA stop job is running for Advanced key-value storeā€

Full error Report:
Internal Server Error

The server encountered an internal error and was unable to complete your request.
Please contact the server administrator if this error reappears multiple times, please include the technical details below in your report.
More details can be found in the server log.

Ahh I found the Solution!

In my case the problem was just that I copied to much on my SD card on the Respberry. I just had to make some space and reboot and everything was working angain.