Not enough free space message on windows client

Nextcloud version : 17
Operating system and version: Ubuntu 18.04.3
Apache or nginx version: Apache 2.4.29
PHP version:7.2

I try to synchronize on my windows 10 laptop with my nextcloud and I get the message that there is not enough free space to upload some files. On my linux server I still have 50gb free space.

Is this the first time you’ve seen this error? (Y/N): Y

Steps to replicate it:

The output of your config.php file in /path/to/nextcloud (make sure you remove any identifiable information!):

$CONFIG = array (
  'instanceid' => 'xxx',
  'passwordsalt' => 'xxx',
  'trusted_domains' =>
  array (
    0 => '10.0.0.9',
    1 => 'xxx.xxx.me',
  ),
  'datadirectory' => '/var/www/xxxx/data',
  'dbtype' => 'mysql',
  'version' => '17.0.2.1',
  'dbname' => 'owncloud',
  'dbhost' => 'localhost',
  'dbtableprefix' => 'oc_',
  'dbuser' => 'xxxx',
  'enable_previews' => false,
  'overwriteprotocol' => 'https',
  'dbpassword' => 'xxx',
  'installed' => true,
  'mail_from_address' => 'nas',
  'mail_smtpmode' => 'smtp',
  'mail_domain' => 'xxx.net',
  'forcessl' => true,
  'theme' => '',
  'secret' => 'xxx',
  'appstore.experimental.enabled' => false,
  'loglevel' => 1,
  'logtimezone' => 'Europe/Berlin',
  'trashbin_retention_obligation' => 'auto',
  'maintenance' => false,
  'updatechecker' => false,
  'overwrite.cli.url' => '/owncloud',
  'htaccess.RewriteBase' => '/owncloud',
  'versions_retention_obligation' => 'auto, 5',
  'memcache.local' => '\\OC\\Memcache\\APCu',
  'memcache.locking' => '\\OC\\Memcache\\Redis',
  'filelocking.enabled' => 'true',
  'redis' =>
  array (
    'host' => '/var/run/redis/redis.sock',
    'port' => 0,
    'timeout' => 0.0,
  ),
  'mail_smtphost' => 'xxxx.xxxx.net',
  'mail_sendmailmode' => 'smtp',
  'mail_smtpauthtype' => 'LOGIN',
  'mail_smtpauth' => 1,
  'mail_smtpport' => '587',
  'mail_smtpname' => 'xxx@xxx.net',
  'mail_smtppassword' => 'xxx',
  'mail_smtpsecure' => 'tls',
  'updater.secret' => 'xxxx',
);

The output of your Apache/nginx/system log in /var/log/____:

error log shows:
[Fri Jan 10 10:03:02.334141 2020] [core:notice] [pid 24573] AH00094: Command line: '/usr/sbin/apache2'
[Fri Jan 10 10:07:23.767249 2020] [autoindex:error] [pid 24609] [client 10.0.0.138:52349] AH01276: Cannot serve directory /var/www/owncloud: No matching DirectoryIndex (none) found, and server-generated directory index forbidden by Options directive

Make sure that you’ve set the user quota correctly. This can be done under the user management.

user has unlimited space.

make sure that you don’t wanna sync more than 50GB at once.

It not more than 1gb that is newly added

do you have NC installed as a docker, vm, snap?

Direct without any special containers

where does your data-directory link to?

it is an own partition with free space (just mounted local ext4 fs).