[BUG] Native desktop app (ARM64 Windows) crashes exclusively during tool use — corrupted ANSI codes at tool-call boundaries

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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Environment

• OS: Windows 11 Home, ARM64, Build 26200
• CPU: Snapdragon X 10-core X1P64100 @ 3.40 GHz
• Claude Code native app version: 2.1.63 (desktop installer)
• npm version (workaround): @anthropic-ai/claude-code@2.1.63 under Node.js v22.20.0 (x64 emulated)

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Behavior

The native desktop app crashes only during tool use — every time, on every tool type (Bash, file reads/writes, web
fetches). Pure text conversations with no tool calls complete without issue. The app does not display an error; it
simply stops mid-session, starting a new session on next launch.

Observable leading indicator before crash: When copying bash commands from the tool-call UI, trailing characters ]pm
appear at the boundary of the copied text. These are corrupted ANSI reset sequences (\033[0m rendered as literal ]pm),
suggesting the native app's tool-call rendering or IPC layer is mishandling escape sequences on ARM64.

Crash is consistent and reproducible — occurred across dozens of sessions on
the same hardware.

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What does NOT crash

• Pure text conversations
• The npm version (@anthropic-ai/claude-code) running in Windows Terminal — fully stable, tool calls survive correctly

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Diagnosis

Both the native app and the npm version run x64 binaries under Windows ARM64 emulation (confirmed via PE header check
on node.exe: Machine: 0x8664). The difference is the Electron rendering layer present in the native app but absent in
the npm version. The crash appears to be in the Electron tool-call IPC or terminal rendering path, not in the Bun
runtime (the Bun alignment fix shipped in v2.1.53; crashes continued through v2.1.63 on this machine).

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Related issues

• #20869 — Native exe crashes, npm version works (same workaround, less diagnostic detail)
• #28184 — Same hardware profile (Snapdragon X, Build 26200), desktop app crash during sessions; root cause attributed

to yukonSilver VM — may be a separate failure mode

• #26724 / #27258 — Bun alignment panic on ARM64 (different crash; fixed in v2.1.53)

What Should Happen?

run without crashing 🤷

Error Messages/Logs

Steps to Reproduce

see description.

Claude Model

Sonnet (default)

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

2.1.63

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

Windows Terminal

Additional Information

_No response_