Read this please:
You didn’t provide any information about your server. Plus, everything you write suggests that you haven’t bothered to read the manuals yet. So how about starting now?
Here some entry points concearning your issue:
-
https://docs.nextcloud.com/server/latest/admin_manual/issues/general_troubleshooting.html#logfiles
-
Configuration Parameters — Nextcloud latest Administration Manual latest documentation
-
Logging — Nextcloud latest Administration Manual latest documentation
Much luck,
ernolf