Problems logging into Gibbon

Hi Ross, Hope you are well.
Recently I have noticed that when i initially log in to gibbon i get this endless loading image ( see attach). When i click on any of the tabs it states that I do not have access. Then upon re-entering my login info I am able to get access (see attachment) to the system and this problem will occur on any PC I am using.
Any possible solutions?

Willpro, this one is new to us, and so I don’t have an instant solution for you. Can you let me know what version you are using. I am guessing v12, which is the latest stable version, but just want to check. Can you check your server logs to see if you are getting any errors on loading this page? Cheers, Ross.

I am seeing an error message like this with the “X” representing site info:
[Mon Oct 10 09:46:47 2016] [error] [client] File does not exist: /xxxx/xxxxxxx/public_html/, referer: .
What amazes me it only happens at one location that i am at in the days and it seems to happen on all four computers except the tablet or my phone but its fine working from home.

This version is ver.11

Willpro, this is very weird, and it sounds very much like a local network issue. Gibbon has no file called 404.shtml, and so something might be doing some local translation of URLs. Can you use Inspect Element in Firefox, and switch to the Network tab to try and see what is going on?