Nextcloud version (eg, 20.0.5): 23.0.2
Operating system and version (eg, Ubuntu 20.04): Raspbian Buster
Apache or nginx version (eg, Apache 2.4.25): Apache 2.4
PHP version (eg, 7.4): 8.0
First off, I’m a major amateur, trying to make a self hosted version of Nextcloud work. My apologies behorehand 
I was on PHP 7.3 when Nextcloud warned me it was time to update to PHP 8.0. So I did, via terminal.
Now, when I run php -v , I learn Raspbian has in fact switched to PHP 8.0. I suspect Nextcloud (or Apache??) are not?
When I go to https://MYDOMAIN.nl/nextcloud I get an ‘Internal Server Error’ without too many specifics.
I can’t seem to find what I did wrong and how to even start to repair it.
Thank you very much for any help.
Is this the first time you’ve seen this error? (Y/N): Yes
The output of your config.php file
<?php
$CONFIG = array (
'instanceid' => 'XXX',
'passwordsalt' => 'XXX',
'secret' => 'XXX',
'trusted_domains' =>
array (
0 => '192.168.1.XXX',
1 => 'XXXXXXXX.nl',
2 => 'www.XXXXXXXXX.nl',
),
'datadirectory' => '/mnt/dikzak/data',
'dbtype' => 'mysql',
'version' => '23.0.0.10',
'overwrite.cli.url' => 'http://192.168.1.XXX/nextcloud',
'dbname' => 'nextclouddb',
'dbhost' => 'localhost',
'dbport' => '',
'dbtableprefix' => 'oc_',
'mysql.utf8mb4' => true,
'dbuser' => 'XXXXXXXXXX',
'dbpassword' => 'XXXXXXXXX',
'installed' => true,
'memcache.local' => '\OC\Memcache\APCu',
'maintenance' => false,
'theme' => '',
'loglevel' => 2,
);
The output of your Apache/nginx/system log in /var/log/____:
[Thu Feb 17 15:52:18.211704 2022] [ssl:warn] [pid 1624] AH01909: 127.0.1.1:443:0 server certificate does NOT include an ID which matches the server name
[Thu Feb 17 15:52:18.325251 2022] [ssl:warn] [pid 1625] AH01909: 127.0.1.1:443:0 server certificate does NOT include an ID which matches the server name
[Thu Feb 17 15:52:18.344574 2022] [mpm_prefork:notice] [pid 1625] AH00163: Apache/2.4.38 (Raspbian) OpenSSL/1.1.1d configured -- resuming normal operations