Nextcloud dont respond, solved

Hello,

Before, sorry for my english, im not native.

I installed Nextcloud last week on debian Debian netinst, P8400M, 4go fo RAM, installed in 2015.

Nextcloud work well, I created one account and begin synchronisation. Work perfectly.
Try with another account, work always well.
After, i push nextcloud in “production”, with 100Go, 2700 files. Synchronisation begins, and stop after 3hours (10Mbit/s).
The nextcloud server stuck and dont respond (gray icon on client).

When the event appear, the server is very slow (ssh), lot of apache2 appear.
ps -aux :

error.log :

`

[core:notice] [pid YYY] AH00052: child pid XXX exit signal Segmentation fault (11)
`

I need to stop apache2 with “service apache2 stop” maybe 10 or 20 times, stop the faulty client (win7), reboot the server. Sometime two times if all apache2 process are not down.

The error on the faulty client fail come when he try to synchronise 3 files, 600Mo each.
Same files/directory on the other client, no problem …

I add one character to the directory, restart nextcloud 2 time, and synchronisation work …
I dont know if the problem come from the client or the server.

What versions of Apache/MySQL/PHP are you using?

Apache/2.4.25 (Debian)
Server version: 10.1.23-MariaDB-9+deb9u1 Debian 9.0
PHP 7.0.19-1

I configured Redis instead Memcached : https://docs.nextcloud.com/server/9/admin_manual/configuration_server/caching_configuration.html#id4
Removed the files, and everything fine.