There is some issue on server side which making IIS not responding again and again We are going to take it off from network for some moment to check it. We will update soon.
The server is back online now, we're keeping a watch on it and its had some very high RAM use. I'm looking around some today to see if I can find some suitable RAM to upgrade the server as well, which would help with an immediate boost, but of course would require a downtime again to install. I will keep posted here if we do upgrade the RAM.