[BUG]Claude Code desktop app, AWS Bedrock, us-east-2, "invalid model identifier" error, started today, two machines affected, one machine that is the root user on AWS Bedrock is working fine through Claude Code -working fine with identical credentials.

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?

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API Error (claude-opus-4-6): 400 The provided model identifier is invalid.. Try --model to switch to us.anthropic.claude-opus-4-1-20250805-v1:0.

What Should Happen?

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API Error (claude-opus-4-6): 400 The provided model identifier is invalid.. Try --model to switch to us.anthropic.claude-opus-4-1-20250805-v1:0.

Error Messages/Logs

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API Error (claude-opus-4-6): 400 The provided model identifier is invalid.. Try --model to switch to us.anthropic.claude-opus-4-1-20250805-v1:0.

Steps to Reproduce

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API Error (claude-opus-4-6): 400 The provided model identifier is invalid.. Try --model to switch to us.anthropic.claude-opus-4-1-20250805-v1:0.

Claude Model

Sonnet (default)

Is this a regression?

Yes, this worked in a previous version

Last Working Version

opus 4.6

Claude Code Version

An API error occurred Try sending your message again. View details API Error (claude-opus-4-6): 400 The provided model identifier is invalid.. Try --model to switch to us.anthropic.claude-opus-4-1-20250805-v1:0.

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

PowerShell

Additional Information

<img width="3840" height="1332" alt="Image" src="https://github.com/user-attachments/assets/8535bb5a-dbbd-416f-a7c0-4c7b198f0199" />