[BUG] Cowork Browser pane: concurrent background sessions crash the GPU process and take down the whole app

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?

When running multiple concurrent background sessions that each use the Claude Browser pane (mcp__Claude_Browser__* tools) for web automation, the Chromium GPU process crashes within minutes ("GPU process gone: reason=crashed"), which takes down the entire desktop app. The app window disappears instantly with no error dialog. This has reproduced 3 times, including once right after a clean reboot with an updated GPU driver, so it isn't a driver issue.

What Should Happen?

The app should handle multiple concurrent Browser-pane sessions without crashing the shared GPU process, or at minimum, a failing background pane should only affect that one session instead of taking down the whole app.

Error Messages/Logs

From %LOCALAPPDATA%\Packages\Claude_pzs8sxrjxfjjc\LocalCache\Roaming\Claude\logs\main.log:
15:21:09 [info] Starting app
15:24:35 [info] GPU process gone: { type: 'GPU', reason: 'crashed', exitCode: 34, serviceName: 'GPU' }
13:08:10 [info] GPU process gone: { type: 'GPU', reason: 'crashed', exitCode: 101457950, serviceName: 'GPU' }
13:25:38 [info] GPU process gone: { type: 'GPU', reason: 'crashed', ... }
Also seen repeatedly whenever a Browser pane isn't the one shown in the foreground:
error: Error: Screenshot timed out after 5s: the Browser pane is not displayed, so the page is not compositing frames. Display the pane and retry.
Side effect: after the crash, the main app process disappears entirely from Task Manager, but a separate Windows service (CoworkVMService / cowork-svc.exe) keeps running independently, which then makes Windows' "Repair app" feature refuse to run ("app is still active").

Steps to Reproduce

1. Open Claude Desktop.
2. Start 3 (or more) background agent tasks in the same session, each instructed to use the Claude Browser pane (mcp__Claude_Browser__computer / navigate tools) to browse and screenshot different websites concurrently.
3. Wait a few minutes while all 3 run in parallel.
4. Observe the entire desktop app disappear instantly, with no error message.
5. Confirmed NOT caused by GPU driver: reproduced again immediately after updating the NVIDIA driver to the latest version and rebooting.

Workaround: running the same automation sequentially (one Browser-pane session at a time) avoids the crash.

Claude Model

None

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

1.24012.9

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

Other

Additional Information

_No response_