[BUG] Claude Desktop crashes on launch when Cowork or Claude Code loads — chat works — since macOS Tahoe 26.3.1 update, persists through clean reinstall and OS upgrade to 26.4.1

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 Desktop crashes on launch when Cowork or Claude Code loads — chat works — since macOS Tahoe 26.3.1 update, persists through clean reinstall and OS upgrade to 26.4.1

Environment

Device: MacBook Pro 14-inch, November 2024 (Apple M4)
Memory: 32GB
macOS: Tahoe 26.4.1 (issue began on 26.3.1)
Claude Desktop version: latest (auto-updated overnight)

What's happening

Claude Desktop crashes on every launch since an overnight auto-update to macOS 26.3.1 (Rapid Security Response), which coincided with what appears to be a Claude Desktop auto-update. Chat-only functionality works — the crash is specifically triggered by the Cowork or Claude Code components loading on startup.
Importantly, Claude Desktop was working normally on Tahoe 26.2 and 26.3, so this is not a blanket Tahoe incompatibility — something specific changed at 26.3.1.

Steps taken to resolve

Killed all Claude processes via Activity Monitor — main Claude process was at 113% CPU on launch
Uninstalled and reinstalled Claude Desktop multiple times — no change
Deleted entire ~/Library/Application Support/Claude folder and reinstalled fresh
On first post-clean-install launch, app opened briefly and partially loaded, then crashed when attempting to load Claude Code
Second launch crashed faster than the first
Updated macOS to 26.4.1 — issue persists

Expected behaviour

Claude Desktop launches fully including Cowork and Claude Code, as it did on Tahoe 26.2 and 26.3.
Additional context
Another app (Wispr Flow) also stopped working at the same time, suggesting the macOS 26.3.1 Rapid Security Response update may have introduced a system-level change affecting certain apps.

Happy to provide log files or further diagnostic info if helpful.

What Should Happen?

Claude Desktop launches fully including Cowork and Claude Code, as it did on Tahoe 26.2 and 26.3.
Additional context
Another app (Wispr Flow) also stopped working at the same time, suggesting the macOS 26.3.1 Rapid Security Response update may have introduced a system-level change affecting certain apps.

Error Messages/Logs

Claude Desktop crashes on every launch since an overnight auto-update to macOS 26.3.1 (Rapid Security Response), which coincided with what appears to be a Claude Desktop auto-update. Chat-only functionality works — the crash is specifically triggered by the Cowork or Claude Code components loading on startup.
Importantly, Claude Desktop was working normally on Tahoe 26.2 and 26.3, so this is not a blanket Tahoe incompatibility — something specific changed at 26.3.1.

Steps to Reproduce

Steps to Reproduce

Run Claude Desktop on macOS Tahoe 26.2 or 26.3 — app launches and runs normally
Allow macOS to auto-update to 26.3.1 (Rapid Security Response)
Launch Claude Desktop — app crashes on every attempt
Crash appears to be triggered specifically when Cowork or Claude Code components load on startup
Issue persists through full uninstall/reinstall, deletion of ~/Library/Application Support/Claude, and upgrading macOS to 26.4.1

Claude Model

None

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

Claude Desktop version: 1.2581.0

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Terminal.app (macOS)

Additional Information

_No response_