The connection to authserver.mojang.com can no longer be established because none of the server's cipher suites are supported by the launcher.
This is most likely because it relies on the operating system to support these.
On the ssllabs report you can see that IE11 on Windows 7 and 8.1 can not connect.
Relevant lines from the launcher log:
[Info: 2021-10-06 10:31:34.6695672: NetQueue.cpp(428)] NetQueue: Primary ip: 13.225.75.47, Host: authserver.mojang.com
[Info: 2021-10-06 10:31:34.6695982: NetQueue.cpp(466)] NetQueue: Action failed with result "schannel: next InitializeSecurityContext failed: SEC_E_ILLEGAL_MESSAGE (0x80090326) - This error usually occurs when a fatal SSL/TLS alert is received (e.g. handshake failed). More detail may be available in the Windows System event log." (35) : https://authserver.mojang.com/refresh
[Info: 2021-10-06 10:31:34.6696394: NetQueue.cpp(504)] NetQueue: Action finished: https://authserver.mojang.com/refresh
[Info: 2021-10-06 10:31:34.6696607: NetQueue.cpp(527)] NetQueue: Action failed in finalization: https://authserver.mojang.com/refresh
[Info: 2021-10-06 10:31:34.6697263: EndpointAPI.cpp(131)] Error: schannel: next InitializeSecurityContext failed: SEC_E_ILLEGAL_MESSAGE (0x80090326) - This error usually occurs when a fatal SSL/TLS alert is received (e.g. handshake failed). More detail may be available in the Windows System event log., Code: 0Comments 2
I was running into a similar issue with launchermeta servers (and probably all the other servers given the nature of the issue).
I'm now curious if I actually fixed my issue locally (because I missed some updates) or if I incidentally did all that while Mojang fixed things on their end.
This issue can be resolved permanently by Mojang by having the launcher handle TLS itself, rather than relying on the Windows SCHANNEL toolkit since Win7 and Win8 won't have continued support for newer TLS ciphers and protocols. And this is absolutely doable because browsers like Chrome do it already --you could see the launchermeta json URLs in Chrome despite the launcher failing the handshake because only the latter goes through SCHANNEL.
This is probably the preferable solution in the long term, since it means not dropping Win7/8 support, nor having to allow weaker ciphers indefinitely as the technology progresses.
ETA: probably moot to comment on a closed ticket, but I'm not sure if I should raise a new ticket for this because it's less "bug" and more "feature request".
Can confirm that this was a real issue. I saw the same errors in my launcher since Monday, but it took time to diagnose. No further information was logged in the Windows System event log. Wireshark showed that authserver.mojang.com would respond with notify_close after receiving a list of cipher suites.
Edit: My thanks to whoever rolled back this change. Phew!