The server has moved and this has caused some downtime. The reason for server move is cost reasons. Perhaps next time it will go a bit more smoothly.
New IP should is 188.8.131.52 but you don't have to configure it anywhere. Ask on NSL discord if you have problems with the page.
The might be still another server move but this time server IP won't change. In fact all that happens is server goes down for 1-2 hours and the website server will boot with same IP, data etc. but with different hardware.
Most of ENSL stuff is available in open-source repos (feel free to contribute). You can see the repo's here. I have added repositores for both NS1 server and ENSL Plugin, and added respective Dockerfiles to make them build automagically. Docker is an useful tool to basically run anything like ENSL server or NS1 server on any computer with a few simple commands without having to install things manually. This makes it easy to create automated builds for almost anything. There's also forked repository of NS1 source code and hopefully we'll get some updates to NS1.
You can send website feedback via this thread, the contact form or github issues. Especially if any new isues have risen up.