Nextcloud client start removing files

Nextcloud version (eg, 12.0.2): 17
Operating system and version (eg, Ubuntu 17.04): Debian
Apache or nginx version (eg, Apache 2.4.25): Apache
PHP version (eg, 7.1): 7.2

The issue you are facing: The windows nextcloud client seems to have randomly deleted some of my data. I have found several topics of people facing the same problem. Is there any solution for this? This is totaly unacceptable and makes the total system unreliable. I would like to use Nextcloud again, but I cannot take the risk of losing my files.

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

Steps to replicate it:

The output of your Nextcloud log in Admin > Logging:

https://pastebin.com/2VVvk0Rj (it was too long to paste it here)

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

PASTE HERE

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

[Wed Apr 15 00:00:05.885138 2020] [mpm_prefork:notice] [pid 1096] AH00163: Apache/2.4.38 (Raspbian) OpenSSL/1.1.1d configured -- resuming normal operations
[Wed Apr 15 00:00:05.885257 2020] [core:notice] [pid 1096] AH00094: Command line: '/usr/sbin/apache2'
[Wed Apr 15 09:24:33.542423 2020] [access_compat:error] [pid 20790] [client 81.164.138.117:49271] AH01797: client denied by server configuration: /var/www/html/config
[Wed Apr 15 22:41:04.101188 2020] [access_compat:error] [pid 2305] [client 81.164.138.117:49289] AH01797: client denied by server configuration: /var/www/html/config
[Wed Apr 15 22:48:45.136081 2020] [core:notice] [pid 1096] AH00052: child pid 2432 exit signal Segmentation fault (11)
[Wed Apr 15 22:48:45.436544 2020] [mpm_prefork:notice] [pid 1096] AH00169: caught SIGTERM, shutting down
[Wed Apr 15 22:49:30.245277 2020] [mpm_prefork:notice] [pid 1101] AH00163: Apache/2.4.38 (Raspbian) OpenSSL/1.1.1d configured -- resuming normal operations
[Wed Apr 15 22:49:30.252270 2020] [core:notice] [pid 1101] AH00094: Command line: '/usr/sbin/apache2'
[Wed Apr 15 22:50:40.296467 2020] [access_compat:error] [pid 1129] [client 81.164.138.117:53983] AH01797: client denied by server configuration: /var/www/html/config
[Wed Apr 15 23:13:30.791437 2020] [access_compat:error] [pid 3042] [client 192.168.0.98:57388] AH01797: client denied by server configuration: /var/www/html/config
[Wed Apr 15 23:30:01.819468 2020] [access_compat:error] [pid 2306] [client 192.168.0.98:58112] AH01797: client denied by server configuration: /var/www/html/config
[Wed Apr 15 23:37:00.752428 2020] [access_compat:error] [pid 4258] [client 81.164.138.117:53509] AH01797: client denied by server configuration: /var/www/html/config
[Wed Apr 15 23:37:57.219545 2020] [access_compat:error] [pid 1524] [client 81.164.138.117:56630] AH01797: client denied by server configuration: /var/www/html/config
[Thu Apr 16 00:00:05.208321 2020] [mpm_prefork:notice] [pid 1101] AH00171: Graceful restart requested, doing restart
AH00558: apache2: Could not reliably determine the server's fully qualified domain name, using 127.0.1.1. Set the 'ServerName' directive globally to suppress this message