[BUG]AskUserQuestion prompt flashes and disappears — task then hangs indefinitely or app UI vanishes, requiring force quit

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?

Description:
The multiple-choice question widget (AskUserQuestion) sometimes appears on screen and disappears again within a split second, before it can be read or answered. When this happens, the agent gets stuck — the task stops making any progress. This seems to be part of a broader pattern of UI elements failing to render: two different failure modes have followed the vanishing prompt, and the app's own "About" window also opens blank rather than showing version info.

The loading/thinking indicator keeps running indefinitely with no further progress or response. I waited 30 minutes on one occasion before giving up and manually interrupting.
The entire app UI breaks — everything vanishes from the screen — and I have to force-quit and restart the app to recover.
Separately (possibly related): Claude → About Claude opens a blank window instead of showing version info.

What Should Happen?

Expected behavior: The question prompt should stay visible until answered, and if it fails to render properly, the task should surface an error rather than hanging silently or corrupting the app UI. The About window should display version info.

Actual behavior: Prompt flashes and disappears; task hangs with no visible error, sometimes indefinitely; app UI occasionally goes blank/vanishes and requires a force quit; About window also renders blank.

Frequency: Several times a day recently.

Error Messages/Logs

Steps to Reproduce

Steps to reproduce:

• Be in an active Cowork session where Claude calls a question/clarification prompt (AskUserQuestion) mid-task.
• Observe the prompt widget render and then disappear almost immediately.
• Wait — the task does not resume or continue, in some cases even after 30+ minutes.
• In some cases the app UI itself becomes unresponsive/blank, requiring a full quit and relaunch.
• Separately: open Claude → About Claude from the menu bar — window opens blank.

Claude Model

Sonnet (default)

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

1.24012.9

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Terminal.app (macOS)

Additional Information

_No response_