[BUG] "Unhandled case: [object Object]" Intermittent stall errors when Claude asks operator a question. Similar to #59120 but specific trigger.

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?

During a session, Claude surfaces a question, but VS Code plugin throws error and processing stops. No question dialog is shown.:
Unhandled case: [object Object]

View output logs · Troubleshooting resources

Claude says this about the log:
That error is coming from the VSCode extension's UI layer, not from Claude itself. Here's what the logs show:

What happened:

Request went out at 12:43:10, stream started at 12:43:12
Stream stalled for ~37s, then ended with sdk_stream_ended_no_result and had_error: true (12:43:42)
Right after, an AskUserQuestion permission hook fired (12:44:08)
What "Unhandled case: [object Object]" means:
That's a JavaScript switch/default branch in the extension hitting a message variant it doesn't know how to render — the [object Object] is the message payload stringified poorly. Something in the response stream (likely tied to the AskUserQuestion tool call or the mid-stream error)

What Should Happen?

Question dialog should be shown to user for reply.

Error Messages/Logs

2026-05-14 12:43:10.222 [info] From claude: 2026-05-14T16:43:10.222Z [DEBUG] [API:auth] OAuth token check complete

2026-05-14 12:43:10.224 [info] From claude: 2026-05-14T16:43:10.224Z [DEBUG] [API REQUEST] /v1/messages x-client-request-id=85833155-237d-4b5c-ac4d-8e2b11e8d355 source=sdk

2026-05-14 12:43:10.224 [info] Received message from webview: {"type":"request","channelId":"0u5nur2452i","requestId":"j45jcrwyp6","request":{"type":"log_event","eventName":"time_to_response","eventData":{"ttrMs":16}}}
2026-05-14 12:43:12.183 [info] From claude: 2026-05-14T16:43:12.183Z [DEBUG] Stream started - received first chunk

2026-05-14 12:43:27.196 [info] From claude: 2026-05-14T16:43:27.196Z [WARN] [Stall] stream_idle_partial lastChunkAgeMs=15014 bytesTotal=648 idleDeadlineMs=300000

2026-05-14 12:43:42.206 [info] Received message from webview: {"type":"request","channelId":"0u5nur2452i","requestId":"0f0gw1j618j","request":{"type":"log_event","eventName":"sdk_stream_ended_no_result","eventData":{"had_error":true,"subagent_count":0,"message_count":31}}}
2026-05-14 12:43:42.206 [info] Received message from webview: {"type":"request","requestId":"08ya7x7hzo8g","request":{"type":"update_session_state","sessionId":"5f176e65-2091-4a87-8831-11bc7721915f","state":"idle","title":"Review coding session rules and design philosophy"}}
2026-05-14 12:43:49.763 [info] From claude: 2026-05-14T16:43:49.763Z [WARN] Streaming stall detected: 37.6s gap between events (stall #1)

2026-05-14 12:44:06.956 [info] Received message from webview: {"type":"request","requestId":"wjycnnlzlhm","request":{"type":"open_output_panel"}}
2026-05-14 12:44:08.545 [info] From claude: 2026-05-14T16:44:08.545Z [DEBUG] executePermissionRequestHooks called for tool: AskUserQuestion

2026-05-14 12:44:08.551 [info] Received message from webview: {"type":"request","requestId":"ivginqzmue","request":{"type":"rename_tab","title":"Review coding session ru…","hasPendingPermissions":false,"hasUnseenCompletion":false}}
2026-05-14 12:44:08.552 [info] Received message from webview: {"type":"request","requestId":"gpsbgt9mfu8","request":{"type":"update_session_state","sessionId":"5f176e65-2091-4a87-8831-11bc7721915f","state":"idle","title":"Review coding session rules and design philosophy"}}
2026-05-14 12:44:08.599 [info] From claude: 2026-05-14T16:44:08.599Z [WARN] Streaming completed with 1 stall(s), total stall time: 37.6s
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Steps to Reproduce

Indeterminant - though it occurs only during ask question dialogs currently.

Claude Model

Opus

Is this a regression?

Yes, this worked in a previous version

Last Working Version

unknown

Claude Code Version

2.1.141 (VSCode extension, build 7c3)

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

VS Code integrated terminal

Additional Information

Extension version: Claude Code 2.1.141 (VSCode extension, build 7c3)
Model: claude-opus-4-7 (Opus 4.7)
Session ID: 5f176e65-2091-4a87-8831-11bc7721915f
Permission mode: acceptEdits
The session was resumed (not new) at 12:42:12 and hit the stall/error a minute later. A fresh session spawned at 12:45:28 — so it looks like you (or the extension) reloaded after the "Unhandled case" error.