[BUG] Claude Desktop Helper Plugin Crash (EXC_BREAKPOINT) on Launch

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?

App Version: Claude Desktop 1.1.4328
macOS: 26.4 (25E5207k)
Hardware: Mac16,8 (Apple Silicon, ARM-64)
Date: 2026-02-25

Summary
Claude Helper (Plugin) crashes with EXC_BREAKPOINT / SIGTRAP on every launch. The process lives for approximately 220 milliseconds before crashing. This causes the Claude Desktop window to go blank repeatedly. The crash is reproducible and occurs independent of MCP configuration.

Crash Details

Exception: EXC_BREAKPOINT (SIGTRAP)
Signal: Trace/BPT trap: 5
Faulting Thread: com.apple.main-thread
Process lifetime: ~220ms (launch 18:15:38.720 → crash 18:15:38.941)
Incident ID: C0826516-F905-420C-9520-5D11A09F0592
Bundle ID: com.anthropic.claudefordesktop.helper

Crash Stack Trace (Faulting Thread)
Frame 0: Electron Framework ares_dns_rr_get_ttl + 3406456
Frame 1: Electron Framework ares_dns_rr_get_ttl + 3406260
Frame 2: Electron Framework rust_png$cxxbridge1$Reader$has_exif_chunk + 56320
Frame 3: Electron Framework ares_dns_rr_get_ttl + 3406640
Frame 4: Electron Framework v8::Object::WrapGlobal(v8::Isolate, v8::Local<v8::Object> const&, v8::Object::Wrappable, v8::CppHeapPointerTag) + 230540
Frame 5: Electron Framework node::PrincipalRealm::messaging_deserialize_create_object() const + 533576
Frame 6: Electron Framework ElectronMain + 84
Frame 7: Claude Helper (Plugin) + 40044
Frame 8: dyld start + 6992

Thread State (ARM-64)
PC: 0x000000011f852a8c
LR: 0x000000011f852988
FP: 0x000000016bf237b0
SP: 0x000000016bf232e0
CPSR: 0x60000000
ESR: 0xf2000000 (Breakpoint: brk 0)

Loaded Images (Relevant)
Claude Helper (Plugin) 1.1.4328 base: 0x104178000
Electron Framework 40.4.1 base: 0x10a378000
Squirrel 1.0 base: 0x104208000
ReactiveObjC 3.1.0 base: 0x1043a2000
libffmpeg.dylib base: 0x109d54000

Additional Context

This crash has occurred multiple times today with identical stack traces (earlier incident at 15:28:47, F19D5566-B9EC-4BE9-9DD4-C259D6ABE126).
The crash occurs at the node::PrincipalRealm::messaging_deserialize_create_object() call site inside the Electron Node.js runtime — suggesting an issue in MCP/IPC message deserialization on startup.
Removing all custom MCPs from claude_desktop_config.json did not resolve the crash.
The main Claude process also logs repeated warnings: "This method should not be called on the main thread as it may lead to UI unresponsiveness" from the Security framework, flooding the system log at ~50 entries/second.
macOS SIP is enabled. Developer mode is enabled.

What Should Happen?

Claude Code App shouldn't go blank.

Error Messages/Logs

Steps to Reproduce

Happens when just using Claude Code

Claude Model

Not sure / Multiple models

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

1.1.4328

Platform

Other

Operating System

macOS

Terminal/Shell

Terminal.app (macOS)

Additional Information

_No response_