[BUG] Cowork: every follow-up prompt hangs on "Working through a complex response…" — reproduces on desktop AND claude.ai web

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?

[BUG] Cowork: every follow-up prompt hangs on "Working through a
complex response…" — reproduces on desktop AND claude.ai web

Onset: first observed 2026-08-30, first use after a two-day break.

Behavior:

• First prompt in a session completes normally
• Every subsequent prompt hangs indefinitely on "Working through a

complex response…"

• Cancel button is non-functional — the session cannot be stopped
• Only recovery is a new session, which then fails identically on its

second prompt

Scope: 5 separate Cowork projects, identical behavior in all.

Reproduces in BOTH execution environments:

• Desktop app 1.40609.0 (f65e38), build 2026-08-27T16:19:51Z, macOS

Tahoe 26.6.2 (local VM)

• claude.ai in browser (cloud sandbox)

Since these are separate sandboxes with different hardware, kernel and
network paths, the failure appears to sit in shared session
orchestration rather than in either execution environment.

Ruled out:

• All MCP servers / connectors disabled — still hangs
• All skills disabled — still hangs
• No plugins enabled
• Not project-specific
• macOS 26.6.2 installed 2026-08-26, before a Cowork session that ran

normally on 2026-08-27

Not a duplicate of #45531: there the local VM never initializes. Here
sessions start and the first prompt completes.

Plan: Pro
Suggested label: area:cowork

What Should Happen?

Claude should allow follwup prompts to work without hanging

Error Messages/Logs

Steps to Reproduce

Behavior:

• First prompt in a session completes normally
• Every subsequent prompt hangs indefinitely on "Working through a

complex response…"

• Cancel button is non-functional — the session cannot be stopped
• Only recovery is a new session, which then fails identically on its

second prompt

Claude Model

Not sure / Multiple models

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

Claude 1.40609.0 (f65e38) 2026-08-27T16:19:51.000Z

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Terminal.app (macOS)

Additional Information

_No response_