The Database ist missing some indexes - how to uptdate the database

After the chmod 0644:
drw-r–r-- 2 stefan-franz psacln 4096 Mär 29 08:05 ./
drwxr-x— 15 stefan-franz psaserv 4096 Mär 29 06:13 …/
-rw-r----- 1 stefan-franz psacln 1416 Mär 29 08:05 config.php
-rw-r–r-- 1 stefan-franz psacln 66350 Mär 21 13:02 config.sample.php
-rw-r–r-- 1 stefan-franz psacln 495 Mär 21 13:02 .htaccess
root@h2937523:/var/www/vhosts/stefan-franz.de/nextcloud#

Before:
drwxr-xr-x 2 stefan-franz psacln 4096 Mär 29 08:05 ./
drwxr-x— 15 stefan-franz psaserv 4096 Mär 29 06:13 …/
-rw-r----- 1 stefan-franz psacln 1416 Mär 29 08:05 config.php
-rw-r–r-- 1 stefan-franz psacln 66350 Mär 21 13:02 config.sample.php
-rw-r–r-- 1 stefan-franz psacln 495 Mär 21 13:02 .htaccess

Ho can make it back?

It is a directory:
chmod 0755 /var/www/vhosts/stefan-franz.de/nextcloud/config

I found it: And Nextcloud works again
chmod 0755 /var/www/vhosts/stefan-franz.de/nextcloud/config

Thanks, yes i found it. puhhhh…but maybe here is the reason that i cannot update the database…but here i have no knowledge about that.
I let that message now.

Solution: I added the Indexes manually in the myphpAdmin as here described:
https://stone-edv.de/2022/01/10/nextcloud_missing_indizes/

Thank you for your help