Cannot connect to Zabbix webpage

[scalyback]

We have 3 different networks that are all displaying the same issue when connecting to zabbix web page, I have just returned off of holiday to find all 3 zabbix servers not letting connect so we can monitor the network, with no documentation I am a bit blind as to how the system was setup.

This is the page we get, I have removed the IP but that is the gist of it,

[SanMonitor]

We have 3 different networks that are all displaying the same issue when connecting to zabbix web page, I have just returned off of holiday to find all 3 zabbix servers not letting connect so we can monitor the network, with no documentation I am a bit blind as to how the system was setup.

This is the page we get, I have removed the IP but that is the gist of it,

Seems to be a problem with Apache or Nginx (depending on what is used), I'd firstly check these services on your zabbix server and their logs.