Strange error under setup warnings

Steps to reproduce

I installed an ownCloud instance earlier today and set up memory caching, HSTS, transactional logging etc. By the end on the General Settings, it said everything was fine.
I just set up a second instance on the same server, at the moment with pretty much exactly the same settings as the first one. Having set up all the necessary to deal with the warnings, I have 2 undefined warnings still showing “Error occurred whilst checking server setup”.

Expected behaviour

Well, it would be nice to know what the warnings mean. Then I could deal with them.
I did google it and found a suggestion to check the owncloud.log. I did so and it shows two items, which interestingly are also shown in the log of the working site. I’ll paste them in below

Actual behaviour

So the log says this:

{“reqId”:“uZTz9holYKCn8ibdVeIq”,“level”:3,“time”:“2021-09-02T20:19:31+00:00”,“remoteAddr”:“172.68.186.159”,“user”:"–",“app”:“PHP”,“method”:“POST”,“url”:"/index.php",“message”:“Undefined index: dbconnectionstring at /var/www/owncloud/lib/private/Setup/AbstractDatabase.php#82”}

{“reqId”:“uZTz9holYKCn8ibdVeIq”,“level”:3,“time”:“2021-09-02T20:19:31+00:00”,“remoteAddr”:“172.68.186.159”,“user”:"–",“app”:“mysql.setup”,“method”:“POST”,“url”:"/index.php",“message”:“Specific user creation failed: An exception occurred while executing ‘SELECT user FROM mysql.user WHERE user=?’ with params [“oc_admin”]:\n\nSQLSTATE[42000]: Syntax error or access violation: 1142 SELECT command denied to user ‘username’@‘localhost’ for table ‘user’”}

Server configuration

Operating system:
Debian 11
Web server:
Apache
Database:
MariaDB
PHP version:
7.4.21
ownCloud version: (see ownCloud admin page)
10.8.0.4
Updated from an older ownCloud or fresh install:
Fresh

Where did you install ownCloud from:
download the tarball

Signing status (ownCloud 9.0 and above):

Login as admin user into your ownCloud and access 
http://example.com/index.php/settings/integrity/failed 
paste the results into https://gist.github.com/ and puth the link here.

No need to paste: all it says is “No errors have been found”

The content of config/config.php:

?php
$CONFIG = array (
‘instanceid’ => ‘ocqjqznq71k0’,
‘passwordsalt’ => ‘’,
‘secret’ => ‘/’,
‘trusted_domains’ =>
array (
0 => ‘myserver’,
),
‘datadirectory’ => ‘/var/www/owncloud/data’,
‘overwrite.cli.url’ => ‘https://myserver’,
‘dbtype’ => ‘mysql’,
‘version’ => ‘10.8.0.4’,
‘dbname’ => ‘db’,
‘dbhost’ => ‘localhost’,
‘dbtableprefix’ => ‘oc_’,
‘mysql.utf8mb4’ => true,
‘dbuser’ => ‘user’,
‘dbpassword’ => ‘pword’,
‘logtimezone’ => ‘Africa/Johannesburg’,
‘apps_paths’ =>
array (
0 =>
array (
‘path’ => ‘/var/www/owncloud/apps’,
‘url’ => ‘/apps’,
‘writable’ => false,
),
1 =>
array (
‘path’ => ‘/var/www/owncloud/apps-external’,
‘url’ => ‘/apps-external’,
‘writable’ => true,
),
),
‘installed’ => true,
‘memcache.local’ => ‘\OC\Memcache\APCu’,
‘filelocking.enabled’ => true,
‘memcache.locking’ => ‘\OC\Memcache\Redis’,
‘redis’ =>
array (
‘host’ => ‘localhost’,
‘port’ => 6379,
‘timeout’ => 0,
),
);

List of activated apps:
The default. Have not added any yet.

If you have access to your command line run e.g.:
sudo -u www-data php occ app:list
from within your ownCloud installation folder.

Are you using external storage, if yes which one: local/smb/sftp/…
No
Are you using encryption: yes/no
https? yes
Are you using an external user-backend, if yes which one: LDAP/ActiveDirectory/Webdav/…
no

With access to your command line run e.g.:
sudo -u www-data php occ ldap:show-config
from within your ownCloud installation folder

Response: there are no commands defined in the “ldap” namespace.


### Client configuration
**Browser:**
Chrome
**Operating system:**
Linux Mint 20
### Logs
#### Web server error log

Insert your webserver log here

Since finalising set up of the site, there are a few of these:

[Thu Sep 02 22:48:38.770396 2021] [authz_core:error] [pid 56321] [client 172.68.186.109:58834] AH01630: client denied by server configuration: /var/www/owncloud/data/htaccesstest.txt


#### ownCloud log (data/owncloud.log)

see above


#### Browser log

Insert your browser log here, this could for example include:

a) The javascript console log
b) The network log
c) …
If you don’t mind I’ll leave this unless essential

Hoping I’ve given a bit of info to help identify what these strange errors are. Thank you.

Set up site again from scratch. This time it didn’t come up with weird messages. So I guess that is a fix.