Unable to access document page on CRM

Unable to access document page on CRM

I am unable to access the documents tab in CRM, all the other tabs seem to be working fine, when I am using Safari its blank, in firefox it says:

Server not found

Firefox can’t find the server at docs.zoho.com.

    Check the address for typing errors such as ww.example.com instead of www.example.com
    If you are unable to load any pages, check your computer’s network connection.
    If your computer or network is protected by a firewall or proxy, make sure that Firefox is permitted to access the Web.

I have called 2 times and the issue has not been fixed.