[BUG] Windows desktop app (Code tab): after "Main webview is unresponsive, will kill and reload" the UI never recovers; F5 does nothing, and only quitting (which stops all running Code sessions) fixes it

Preflight Checklist

• [x] I have searched existing issues. Closest: #97234 (Linux, same end state, different trigger), #93925 (macOS), #92677 (Windows, closed by the triage bot as "not about Claude Code"; it is, because the running Code sessions are what gets lost)
• [x] This is a single bug report
• [ ] I am using the latest version of Claude Code: desktop 2.9939.2 bundles Claude Code 2.1.281; npm latest is 2.1.282

What's Wrong?

Claude Desktop on Windows, Code tab, about 8 Code sessions open. Under memory pressure the main process stalled for 34 s and then 44 s, and the watchdog logged Main webview is unresponsive, will kill and reload twice. After that the main view never came back. The web layer's log stops at 18:22:45, nothing about the main view is logged after 18:29, and the window showed only the grey boot skeleton (sidebar placeholders, empty main pane) until the app was quit at 20:53. The rest of the app kept working. Every Code session kept running and stayed usable from the mobile app; only the desktop UI was dead.

What did not help:

• F5 (View → Reload) and F10 (application menu) had no effect. main.log has no Reloading current URL or Redirecting to claude.ai line.
• No error overlay appeared, so there was no Reload button either.
• The only fix was quitting the app, which stopped every running session: [CCD] Stopping 6 active session(s) on quit and [CCD] Killing 9 PTY process tree(s) on quit. After the restart, boot finished in 16 s and the UI worked.

Side note: the stalls were tagged [likely sleep: duration_heuristic], but the machine did not sleep. The Windows System log has no Kernel-Power 42/107 or Power-Troubleshooter 1 events in that window.

What Should Happen?

• If the reloaded main view does not come back, the app should retry or show the load-error overlay with a working Reload.
• View → Reload (F5) should always reload the main view.
• Recovering the UI should never require quitting the app, because quitting kills every running Code session.

Error Messages/Logs

%LOCALAPPDATA%\Claude\Logs\main.log, local time (UTC+2), IDs removed:

18:25:42 [warn] [event-loop-stall] main process blocked for 33850ms [likely sleep: duration_heuristic] (task none, total 4, cumulative 6272ms, rss 371MB)
18:25:49 [info] [process-memory] trigger=interval tree_rss_sum=4178MB tree_footprint_sum=3036MB electron(13)=1632MB children(60)=2546MB top=[electron_renderer:…:808MB electron_main:…:372MB …] sys_free=3864MB/16184MB
18:26:13 [info] Main webview is unresponsive, will kill and reload
18:26:34 [warn] [event-loop-stall] main process blocked for 43612ms [likely sleep: duration_heuristic]
18:26:45 [warn] [event-loop-stall] main process blocked for 10820ms [likely sleep: duration_heuristic]
18:26:50 [info] Main webview is unresponsive, will kill and reload
18:28:19 … 18:29:04 [warn] [event-loop-stall] main process blocked for 509ms … 11674ms (12 stalls)
18:28:25 [warn] [process-memory] process tree read failed { err: 'no answer within 5000ms' }
18:28:39 [info] [process-memory] trigger=stall tree_rss_sum=801MB(electron-only) … electron(12)=801MB … electron_renderer:…:135MB …
(no further main-view lines: no "render process gone", no load failure, no "load recovered")
20:53:25 [info] beforeQuit: handler fired, going down
20:53:25 [info] [CCD] Stopping 6 active session(s) on quit
20:53:25 [info] [CCD] Killing 9 PTY process tree(s) on quit

The renderer that the reload created (seen at 18:28:39) was no longer running at 20:10. The main process, the GPU process and all Claude Code session processes were.

Steps to Reproduce

Not deterministic. What led up to it:

1. Windows 10, 16 GB RAM. Claude Desktop with about 8 Code sessions open for most of the day. The main webview renderer grew to about 750–890 MB, the Claude process tree to about 4.2 GB RSS, and free RAM dropped to about 3.8 GB, with Chrome also running.
2. Memory pressure caused main-process stalls of 10–44 s.
3. The watchdog killed and reloaded the main webview, twice.
4. The main view never returned. F5 and F10 did nothing. Only quitting recovered it, and that stopped the running sessions.

Claude Model

Not sure / Multiple models (a UI bug, not model-related)

Is this a regression?

I don't know

Last Working Version

(unknown)

Claude Code Version

Claude Desktop 2.9939.2 (Squirrel install in %LOCALAPPDATA%\AnthropicClaude), bundled Claude Code 2.1.281

Platform

Anthropic API

Operating System

Windows (Windows 10 Pro 22H2, build 19045)

Terminal/Shell

Other (Claude Desktop Code tab)

Additional Information

• A second Claude Desktop instance (separate --user-data-dir, other account) was running at the same time and was not affected.
• Related: #97234, #93925, #92677, and #81265 (memory growth with embedded sessions).