[BUG] erver-side configuration issue with Anthropic's Azure AD app registration, not a port problem.

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report (please file separate reports for different bugs)
• [x] I am using the latest version of Claude Code

What's Wrong?

include the error AADSTS900971 and client ID
08ad6f98-a4f8-4635-bb8d-f1a3044760f0 so they can fix the app registration.

Same port, same error — this confirms it's a server-side configuration issue with Anthropic's Azure AD app registration,
not a port problem. The localhost redirect URIs simply aren't registered for that client app ID.

What you can do:

1. File a bug report at https://github.com/anthropics/claude-code/issues — include the error AADSTS900971 and client ID

08ad6f98-a4f8-4635-bb8d-f1a3044760f0 so they can fix the app registration.

What Should Happen?

https://github.com/anthropics/claude-code/issues — include the error AADSTS900971 and client ID
08ad6f98-a4f8-4635-bb8d-f1a3044760f0 so they can fix the app registration.

Error Messages/Logs

https://github.com/anthropics/claude-code/issues — include the error AADSTS900971 and client ID
  08ad6f98-a4f8-4635-bb8d-f1a3044760f0 so they can fix the app registration.

Steps to Reproduce

⏺ New URL with a different port (62133). Please try this one:

Click here to authorize Microsoft 365 (https://login.microsoftonline.com/common/oauth2/v2.0/authorize?response_type=code&cl
ient_id=08ad6f98-a4f8-4635-bb8d-f1a3044760f0&code_challenge=IDxLkS8UTSKAJfu-fOIAp9FYE7IcKe0NwAkXayBzsps&code_challenge_meth
od=S256&redirect_uri=http%3A%2F%2Flocalhost%3A62133%2Fcallback&state=IHksl2Imp0xMDWCOOXDcq8Q1uTXGO2ZzMhoH5IvN70k&scope=api%
3A%2F%2F07c030f6-5743-41b7-ba00-0a6e85f37c17%2F.default+offline_access+openid+email&prompt=consent)

Claude Model

Opus

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

2.1.142 (Claude Code)

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Terminal.app (macOS)

Additional Information

_No response_