les log sont archi blindés (184 mo!) sinon voici :
[Tue Nov 01 19:12:52.092284 2016] [suexec:notice] [pid 7833] AH01232: suEXEC mechanism enabled (wrapper: /usr/lib/apache2/suexec)
[Tue Nov 01 19:12:52.136048 2016] [auth_digest:notice] [pid 7834] AH01757: generating secret for digest authentication ...
[Tue Nov 01 19:12:52.136819 2016] [:notice] [pid 7837] FastCGI: process manager initialized (pid 7837)
[Tue Nov 01 19:12:52.180304 2016] [:error] [pid 7834] python_init: Python version mismatch, expected '2.7.5+', found '2.7.9'.
[Tue Nov 01 19:12:52.180376 2016] [:error] [pid 7834] python_init: Python executable found '/usr/bin/python'.
[Tue Nov 01 19:12:52.180380 2016] [:error] [pid 7834] python_init: Python path being used '/usr/lib/python2.7/:/usr/lib/python2.7/plat-x86_64-linux-gnu:/usr/lib/python2.7/lib-tk:/usr/lib/python2.7/lib-old:/usr/lib/python2.7/lib-dynload'.
[Tue Nov 01 19:12:52.180394 2016] [:notice] [pid 7834] mod_python: Creating 8 session mutexes based on 150 max processes and 0 max threads.
[Tue Nov 01 19:12:52.180397 2016] [:notice] [pid 7834] mod_python: using mutex_directory /tmp
[Tue Nov 01 19:12:52.192797 2016] [mpm_prefork:notice] [pid 7834] AH00163: Apache/2.4.10 (Debian) mod_fastcgi/mod_fastcgi-SNAP-0910052141 mod_fcgid/2.3.9 mod_python/3.3.1 Python/2.7.9 mod_scgi/1.13 OpenSSL/1.0.1t configured -- resuming normal operations
[Tue Nov 01 19:12:52.192831 2016] [core:notice] [pid 7834] AH00094: Command line: '/usr/sbin/apache2'
[Tue Nov 01 19:13:18.960632 2016] [:error] [pid 7841] [client 92.129.146.60:65128] PHP Fatal error: require_once(): Failed opening required '/var/www/mon-site/forum/wp-includes/load.php' (include_path='.:/usr/share/php:/usr/share/pear') in /var/www/monsite/forum/wp-load.php on line 51, referer: http://monsite.fr/forum/
[Tue Nov 01 19:13:23.110427 2016] [:error] [pid 7842] [client 92.129.146.60:65129] PHP Fatal error: require_once(): Failed opening required '/var/www/monsite/forum/wp-includes/load.php' (include_path='.:/usr/share/php:/usr/share/pear') in /var/www/monsite/forum/wp-load.php on line 51, referer: http://monsite.fr/forum/
La ligne 51 du fichier wp-load.php :
require_once( ABSPATH . WPINC . '/load.php' );