This windows update seems to have created 3 (?) issues for players:
1. "Hairpin Fix applied. Closing..." / "Sending account ID. Closing..."
(NOT "Sending key... Closing...")
No solution has been found for this issue yet. If you have more information, or something that worked, please post here.
2. Double-entry of password characters.
You can workaround the double-entry by passing your username and password as flags through ashita:

If you have a solution for number 2 and not just the workaround, that'd be really good to know.
3. Unable to progress beyond the ToS agreement.
Keep in mind nas has been working on a new installer and it's possible that they solve these issues somehow, but there's no guarantee, so finding why these occur after the latest Windows update would help a lot of people.