Impossible to start my nextcloud

Hello,
Sorry for langage mistakes. I’m not fluent.
I have just intalled nextcloud on a VPS.
After installation, I try to access my cloud and this is written :

Translation using DeepL :

The server is unable to execute your request.
If this happens again, please send the technical details below to the server administrator.
The server log file may provide more information.

So I went to the log file (/var/log/apache2/error.log). This lines has been added :

[Tue Mar 17 14:36:28.786804 2020] [mpm_prefork:notice] [pid 16942] AH00171: Graceful restart requested, doing restart
[Tue Mar 17 14:36:29.009260 2020] [mpm_prefork:notice] [pid 16942] AH00163: Apache/2.4.38 (Debian) OpenSSL/1.1.1d configured – resuming normal operations
[Tue Mar 17 14:36:29.009278 2020] [core:notice] [pid 16942] AH00094: Command line:
‘/usr/sbin/apache2’

I use some virtual hosts to have my cloud on cloud.website.fr and an other site web on www.website.fr

Do you have an idea about the problem?

Thank you

No real idea. Perhaps it is a problem with SSL. Can you tell us your url to start nextcloud (http vs. https?) Post access.log and other logs.

The file you’ll want to focus on is your nextcloud.log. It will contain the explanation or stack trace for that error. Post an entry generated by your visiting your NC URL and here and we’ll try to help.