LiChess works on some computers on school network but not others

I'm trying to use LiChess for a school chess club. It's crazy - a couple of computers work, but the rest do not, displaying the 'reconnecting' error. The technicians can't figure it out:

· It's not the internet filter or firewall
· There is no proxy server involved
· All machines are similar spec and were ghosted from the same image

Could it be some difference on the machines?
· A difference in Windows updates?
· The .NET version?
· Java version?
· Network card drivers?

Thanks.

No-one? That's a real shame!

I'm now using chessfriends.com, but LiChess is a hundred times better. If this mystery is ever solved, I'll post back.

maybe a too old browser ?

The first thing is that it must not be Internet Explorer. IE has really poor support for WebSockets.

The main thing I'd ask the technicians is to check if the network is properly configured to not block WebSockets (which some education packages do by default). This is a great thing to ask, as a lot of important webapps like Evernote and even some Google services increasingly depend on it.

Java and .NET should have absolutely no effect. Lichess is 100% web native and uses no plugins.

Network drivers shouldn't be an issue either. The WebSockets support is specific to your browser and if the network allows it through, as noted above. Please note that WebSockets is its own protocol, like HTTP or BitTorrent, that is why some networks need special rules for it.

So yes, take the WebSockets question to the technicians and also ask them for Firefox or Chrome support.