I'm not completely sure, but this error is getting spammed:
[2026-03-30 01:35:23.973] [error] [MicrosoftAuthApi] Failed to get access token. Request failed with status code 400. Error: authorization_pending. Error description: AADSTS70016: The provided request has not yet been authorized by the user. The user must input their code. Trace ID: 16100913-1fc0-4a82-82cf-b8e62a094200 Correlation ID: c7bee334-0cb4-4970-8c2c-e62a1b9717de Timestamp: 2026-03-29 14:35:24Z. Error Codes: 70016.
Basically the application is trying to communicate with Microsoft to verify that you own Minecraft, however the request is failing and the app attempt to do it again and again. So it's re-trying to contact Microsoft dozens and dozens of times and waiting to get a successful attempt to finally launch the modpack, but since it's infinitely looping the modpack never launch and the button stay grey.
There is 2 possibilities:
- CurseForge is having issue. Which seems unlikely to me because you are the only one who reported it
- You have a network issue preventing the requests to be successful. This possibility seems more likely to me because the Mojang launcher which acts independently is also having download issues, plus the "missing profile public key" issue you had earlier is sometime caused by a network issue between you and Microsoft