OAuth login fails with 'Authorization failed - Internal server error'

Description

OAuth login flow fails with "Authorization failed - Internal server error" when attempting to authenticate Claude Code CLI.

Environment

• Claude Code version: 2.1.72
• OS: Windows 11 Pro 10.0.26200
• Shell: bash

Steps to Reproduce

1. Run claude in terminal
2. OAuth URL is generated and opened in browser
3. The authorization page at claude.ai/oauth/authorize either:

• Fails to load intermittently, or
• Loads but returns "Authorization failed - Internal server error" (see screenshot below)

1. The CLI times out waiting for the auth code

Screenshot

!Authorization failed - Internal server error

The error page shows:

• "Authorization failed"
• "Internal server error"
• A "Try again" button (which does not resolve the issue)

Additional Context

• Network connectivity to claude.ai and platform.claude.com is confirmed working
• DNS resolution is functional
• This appears to be a server-side issue, not a client-side configuration problem
• Retrying multiple times over several minutes does not resolve the issue