I'm having this issue too now. I've tried everything I can think of for hours. I was able to log in last night with no issues at all, logged out normally.
But tonight I've tried Firestorm, SL official viewer, Alchemy - *ALL* of them stop at "Requesting region capabilities..."
My friend is able to log in as me without an issue, so the problem is my side, either PC, internet, connection.
I've tried changing my DNS to 1.1.1.1, no effect. Tried rebooting PC, rebooting router, turning off Defender temporarily. I have no firewall or antivirus.
Usually I can figure something like this out myself, but I'm completely stumped now. I've raised a support ticket, but who knows when that would get answered!
Has anyone been through this before and worked out what it was? (Running Windows 11, latest viewer versions, ethernet connection)