https://bugs.winehq.org/show_bug.cgi?id=51848
--- Comment #4 from Chiitoo escomk3@hotmail.com --- Indeed, the servers have been taken down, possibly permanently.
However, it's possible to run the client directly by giving it anything as an argument like so:
'Client.exe 123'
At 7.0-rc2 the FPS hangs around 20, so that's an improvement of sorts, but there's still a very fast-flashing UI happening.