[BUG] VSCode extension diff preview fails with CRLF line endings - "String not found in file"

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 version: v2.1.63
Model: Opus 4.6 (Claude Max)
Extension entry: claude-vscode (build 464)
OS: Windows 11 Pro
Error: Error processing client request: Error: String not found in file. Failed to apply edit. when open_diff is triggered on a file with CRLF line endings. Changing the file to LF resolves the issue.

What Should Happen?

Error processing client request: Error: String not found in file. Failed to apply edit. when open_diff is triggered on a file with CRLF line endings. Changing the file to LF resolves the issue.

Error Messages/Logs

[error] Error processing client request: Error: String not found in file. Failed to apply edit.

Steps to Reproduce

use CRLF

Claude Model

None

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

v2.1.63

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Terminal.app (macOS)

Additional Information

_No response_