I’ve seen no recent threads of relevance so…
Nextcloud version 14.0.10.0 (according to config file)
Operating system and version Windows 10. on my computer. Host server is linux.
Apache 2.4.46
PHP version 5.6.40
The issue you are facing:
I am unable to access www.landyvlad.net/nc - my nextcloud installation.
It has been some time since I have used it so have no idea how long this has been happening. It am getting 403 errors (obviously permission issues) and the server error log (which I don;t seem to be able to copy?) shows PHP warnings and htaccess warnings - permission denied.
An earlier thread mentioned that modsecurity interferes with nextcloud and if that is in place that it needs to be disabled for that subdomain. I;ve asked my hosting provider about this and will see what they say.
In any event I am quite lost and would appreciate any assistance you can provide.
Failing that - is it possible to reupload a new set of files (without losing setup/data from before?)
If so a link to the instructions would be great 
Thank you
Is this the first time you’ve seen this error? (Y):
The output of your config.php file in /path/to/nextcloud (make sure you remove any identifiable information!):
<?php
$CONFIG = array (
'instanceid' => 'emoved,
'passwordsalt' => 'removed',
'secret' => 'removed',
'trusted_domains' =>
array (
0 => 'landyvlad.net',
),
'datadirectory' => '/home/landyvla/ncdata',
'overwrite.cli.url' => 'https://landyvlad.net/nc',
'dbtype' => 'mysql',
'version' => '14.0.10.0',
'dbname' => 'landyvla_next995',
'dbhost' => 'localhost',
'dbport' => '',
'dbtableprefix' => 'oc_',
'dbuser' => 'landyvla_next995',
'dbpassword' => 'haha no-',
'installed' => true,
'updater.secret' => 'removed
'maintenance' => false,
'theme' => '',
'loglevel' => 2,
);
The output of your Apache/nginx/system log in /var/log/____:
cant find this directory.