[BUG] [BUG] Pro plan blocked by "Usage credits required for 1M context" — workarounds don't work

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?

Claude Code stopped working overnight on my Pro plan with no prior warning.
Every command throws the same error before any model selection occurs:

API Error: Usage credits required for 1M context · turn on usage credits
at claude.ai/settings/usage, or use --model to switch to standard context

Steps to Reproduce

1. Have an active Claude Pro subscription
2. Open Claude Code in VS Code
3. Send any prompt
4. Error fires immediately, before model selection processes

Expected Behavior

Claude Code should work normally within Pro plan limits.
The 1M context window should NOT be forced on users who never requested it.

Actual Behavior

Claude Code is completely blocked. The error fires at authentication level,
before --model flags or environment variables are processed.

Workarounds Tried (all failed)

• claude --model claude-sonnet-4-6 → same error
• CLAUDE_CODE_DISABLE_1M_CONTEXT=1 → ignored
• Enabling usage credits in settings → error persists

Context

• Plan: Claude Pro
• Tool: Claude Code in VS Code
• OS: Windows
• This worked before. It broke after a recent Claude Code update that

silently changed the default model to one using a 1M token context window.

• Usage limits were NOT exhausted when the error occurred (confirmed in dashboard)

Impact

This is a hard blocker. A paid Pro plan feature stopped working with
zero warning and zero communication from Anthropic. This is unacceptable
for a paid product and breaks professional workflows without notice.

Related Issues

#62063, #63060, #64057, #64398, #65205, #65951

<img width="890" height="468" alt="Image" src="https://github.com/user-attachments/assets/bd23fedf-adda-41d2-82a8-ff36e4f83e27" />

What Should Happen?

Workarounds Tried (all failed)

• claude --model claude-sonnet-4-6 → same error
• CLAUDE_CODE_DISABLE_1M_CONTEXT=1 → ignored
• Enabling usage credits in settings → error persists

Error Messages/Logs

API Error: Usage credits required for 1M context · turn on usage credits at claude.ai/settings/usage, or use --model to switch to standard context

Steps to Reproduce

1. Have an active Claude Pro subscription
2. Open Claude Code in VS Code
3. Send any prompt
4. Error fires immediately, before model selection processes

Claude Model

Not sure / Multiple models

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

2.1.168 (Claude Code)

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

Windows Terminal

Additional Information

_No response_