...on one specific website i keep getting the error message ..SERVER UNREACHABLE...
So the server is down. Unless the site is McAfee, this isn't anything we can help you with. You just have to wait for it to come back up.
...the offline cache of the order entry system is missing some resources......I dnt know what this means
No, I don't know either. It doesn't sound like a McAfee-related issue.