[BUG] Second Claude Code window interrupts immediately on Windows PowerShell (v2.0.56)

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?

• I am using v2.0.56 (not latest, but reproducible across uptime)

What's Wrong?

Second Claude Code window launched in the same Windows uptime
consistently interrupts immediately on first prompt with
"Interrupted · What should Claude do instead?" — no user input
sent. First window in same uptime works fine. Behavior persists
across multiple second-window launches until system reboot.

Expected
Multiple parallel Claude Code windows should run independently
on the same machine.

Actual
Only one window can operate at a time per Windows uptime.
Reboot is the only way to reset and try multi-window operation
again (which then fails again on the second launch).

Environment

• Claude Code: v2.0.56
• OS: Windows (PowerShell 7)
• Shell: PowerShell
• Model: Opus 4.5
• Plan: Claude Max
• Working directories: separate Git repos under

C:\Users\<user>\Documents\GitHub\

Impact
Forces single-window operation on substantial multi-repo work.
Lost productivity from inability to run parallel discovery and
implementation tasks. Yesterday's session and today's session
both affected.

What Should Happen?

Multiple parallel Claude Code windows should run independently
on the same machine.

Error Messages/Logs

"Interrupted · What should Claude do instead?"

Steps to Reproduce

Steps to Reproduce

1. Fresh Windows PowerShell session
2. cd to project directory
3. Run claude (Window 1) — works correctly
4. Open second PowerShell window
5. cd to any project directory
6. Run claude (Window 2)
7. Type any prompt (e.g., "are you working?")
8. Window 2 returns "Interrupted · What should Claude do instead?"

immediately, no execution

Claude Model

Opus

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

Claude Code v2.0.56

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

PowerShell

Additional Information

Related

• #35741 (parallel session interrupts on macOS, v2.1.77+)
• #32386 (Claude Code silently exits mid-task, Windows)
• #11707 (VS Code terminal interrupts, Windows)

Different from those reports: this is v2.0.56, not the recent
2.1.77+ regression. Pattern is reliably reproducible —
"second window in any uptime" is the trigger. Suggests the
issue class extends earlier than 2.1.77 on Windows.