I am running zabbix 3.0 on a virtual machine (which is running centos 7).
Today i ran yum update and got a ton of updates. after the update, my zabbix-server stopped working, similar to what happens here (https://support.zabbix.com/browse/ZBX-10542).
I then restarted the VM, now the zabbix-server works, but the web interface to it doesnt open. i tried checking httpd logs and noticed this error:
[Tue Dec 13 14:08:50.401093 2016] [:error] [pid 1026] [client 192.168.2.235:45294] PHP Warning: require_once(/etc/zabbix/web/maintenance.inc.php): failed to open stream: Permission denied in /usr/share/zabbix/include/classes/core/ZBase.php on line 269
[Tue Dec 13 14:08:50.401176 2016] [:error] [pid 1026] [client 192.168.2.235:45294] PHP Fatal error: require_once(): Failed opening required '/etc/zabbix/web/maintenance.inc.php' (include_path='.:/usr/share/pear:/usr/share/php') in /usr/share/zabbix/include/classes/core/ZBase.php on line 269