[BUG] Cowork: Silent freeze on complex subagent tasks + generated files not locatable (macOS)

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?

Cowork silently freezes when delegating complex tasks to native subagents (defined in .claude/agents/). No spinner, no error, no timeout. Additionally, when tasks do complete, generated files (DOCX) are saved to unpredictable locations and cannot be found with find. Same tasks succeed in Claude Code terminal and Claude Chat. Observed across 5+ sessions, Feb 17-22, 2026. Detailed DOCX report available upon request. Max 20x subscriber, macOS, Claude Desktop 2.1.47

What Should Happen?

Cowork silently freezes when delegating complex tasks to native subagents (defined in .claude/agents/). No spinner, no error, no timeout. Additionally, when tasks do complete, generated files (DOCX) are saved to unpredictable locations and cannot be found with find. Same tasks succeed in Claude Code terminal and Claude Chat. Observed across 5+ sessions, Feb 17-22, 2026. Detailed DOCX report available upon request. Max 20x subscriber, macOS, Claude Desktop 2.1.47

Error Messages/Logs

Steps to Reproduce

1. Open Claude Desktop app (macOS, v2.1.47) and navigate to Cowork
2. Point Cowork to a project folder containing:

• CLAUDE.md (system constitution with agent routing rules)
• .claude/agents/ directory with native subagent .md files (e.g., coo.md with frontmatter: name, description, model, tools)

1. Send a complex task to a specific agent, e.g.:

"COO: Generate a 2026 compliance checklist for 3 Florida LLCs. Check Sunbiz for current status."

1. Wait 15+ minutes. Observe: no response, no spinner, no error, no timeout notification.
2. Try a simplified version (Markdown only, no WebFetch, no DOCX):

"COO: Respond with 'System operational' to confirm you are active."

1. Same result: complete silence. No output.
2. Only recovery: Cmd+Q or killall Claude from Terminal.

ADDITIONAL BUG - Missing output files:

1. On occasions where Cowork DOES complete a task that generates a DOCX file, the file cannot be located.
2. Run: find ~/ -name "*.docx" -newer [timestamp] — no matches for the expected file.
3. The agent does not report the output file path.

COMPARATIVE EVIDENCE:

• Same CLAUDE.md, same .claude/agents/, same tasks → work correctly in Claude Code (terminal)
• Same tasks → work correctly in Claude Chat (web) with Filesystem MCP tools
• Issue is isolated to Cowork environment

Environment: macOS, Claude Desktop 2.1.47, Max 20x subscription
Project: Multi-agent system with 9 native subagents, 9 skills, hooks, rules

Claude Model

Sonnet (default)

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

Claude Desktop 2.1.47 (macOS) Claude Code CLI: installed via native method

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Terminal.app (macOS)

Additional Information

_No response_