[BUG] Agent Teams crashes with "Cannot read properties of undefined (reading 'length')"

Resolved 💬 3 comments Opened Feb 5, 2026 by eugman Closed Feb 7, 2026

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?

Environment:

  • Claude Code version: 2.1.32
  • Node.js version: v25.3.0
  • OS: Windows 10/11
  • Installation method: npm (via Nodist)

Description:
Enabling the experimental Agent Teams feature causes Claude Code to crash immediately with a TypeError.

Workaround:
Disabling the agent teams feature (CLAUDE_CODE_EXPERIMENTAL_AGENT_TEAMS="") allows Claude Code to work normally.

Notes:

  • Claude Code works fine on Node.js v25.3.0 without agent teams enabled
  • The crash appears to be in the React/Ink UI rendering (useSyncExternalStore)

What Should Happen?

Claude Code should launch without errors

Error Messages/Logs

ERROR  Cannot read properties of undefined (reading 'length')

   file:///C:/Program%20Files%20(x86)/Nodist/bin/node_modules/@anthropic-ai/claude-code/cli.js:746:20673

   - x5 (file:///C:/Program%20Files%20(x86)/Nodist/bin/node_modules/@anthropic-ai/claude-code/cli.js:746:20673)
   - z$ (file:///C:/Program%20Files%20(x86)/Nodist/bin/node_modules/@anthropic-ai/claude-code/cli.js:746:28873)
   - FH (file:///C:/Program%20Files%20(x86)/Nodist/bin/node_modules/@anthropic-ai/claude-code/cli.js:746:29029)
   - Object.W9 (file:///C:/Program%20Files%20(x86)/Nodist/bin/node_modules/@anthropic-ai/claude-code/cli.js:746:25216)
   - aV5.useSyncExternalStore (file:///C:/Program%20Files%20(x86)/Nodist/bin/node_modules/@anthropic-ai/claude-code/cli.js:252:9613)
   - T6 (file:///C:/Program%20Files%20(x86)/Nodist/bin/node_modules/@anthropic-ai/claude-code/cli.js:3703:4810)
   - Gjq (file:///C:/Program%20Files%20(x86)/Nodist/bin/node_modules/@anthropic-ai/claude-code/cli.js:7399:13074)
   - b91 (file:///C:/Program%20Files%20(x86)/Nodist/bin/node_modules/@anthropic-ai/claude-code/cli.js:7412:10220)
   - U3 (file:///C:/Program%20Files%20(x86)/Nodist/bin/node_modules/@anthropic-ai/claude-code/cli.js:746:20882)
   - QH (file:///C:/Program%20Files%20(x86)/Nodist/bin/node_modules/@anthropic-ai/claude-code/cli.js:746:39403)

Steps to Reproduce

  1. Set CLAUDE_CODE_EXPERIMENTAL_AGENT_TEAMS=1 in environment or settings.json
  2. Run claude or claude --continue
  3. Claude Code crashes before displaying the UI

Claude Model

Opus

Is this a regression?

No, this never worked

Last Working Version

_No response_

Claude Code Version

2.1.32

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

Other

Additional Information

_No response_

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