I have upgraded from Wheezy to Jessie. (also from Apache 2.2 to Apache 2.4) All is working but I have found these persistent Apache errors. Please, Can somebody confirm if the cause can be the old Apache syntax?: Code: # service apache2 restart Job for apache2.service failed. See 'systemctl status apache2.service' and 'journalctl -xn' for details. # systemctl status apache2.service ? apache2.service - LSB: Apache2 web server Loaded: loaded (/etc/init.d/apache2) Drop-In: /lib/systemd/system/apache2.service.d +-forking.conf Active: failed (Result: exit-code) since mar 2017-05-23 12:29:10 CEST; 18s ago Process: 3668 ExecStart=/etc/init.d/apache2 start (code=exited, status=1/FAILURE) may 23 12:28:50 host.myhost.com apache2: Starting web server: apache2httpd (pid 1577) already running may 23 12:29:10 host.myhost.com apache2: failed! may 23 12:29:10 host.myhost.com apache2: The apache2 instance did not start within 20 seconds. Please read the log files to discover problems ... (warning). may 23 12:29:10 host.myhost.com systemd: apache2.service: control process exited, code=exited status=1 may 23 12:29:10 host.myhost.com systemd: Failed to start LSB: Apache2 web server. may 23 12:29:10 host.myhost.com systemd: Unit apache2.service entered failed state. # /var/log/apache2/error.log [Tue May 23 12:27:02.003960 2017] [access_compat:error] [pid 6334] [client 127.0.0.1:39234] AH01797: client denied by server configuration: /var/www/html/ I have the compatibility module enabled but I'm not sure if still I should replace all the "Order Deny,Allow" syntax in the .conf apache files to end errors. There are a lot!