[BUG] Claude Desktop shows black/blank window on restore (Windows) - React #418 still occurring on v1.1.2156 Body:

[garethsquance-ux]

Preflight Checklist

• I have searched existing issues and this hasn't been reported yet
• This is a single bug report (please file separate reports for different bugs)
• I am using the latest version of Claude Code

What's Wrong?

Description

Claude Desktop frequently shows a completely black/blank window when clicking the app
from the taskbar or restoring it after it's been in the background. The only reliable way
to get the UI to render is to launch the app fresh from the .exe file.

This has been happening consistently for weeks across multiple versions, and is still
present on the latest version (1.1.2156).

Environment

• App version: 1.1.2156 (also occurred on 1.1.1200 / 1.1.351)
• OS: Windows 11 (build 26200)
• CPU: AMD Ryzen 9 9950X3D
• RAM: 128GB
• Claude Code version: 2.1.32

Steps to Reproduce

1. Open Claude Desktop normally
2. Use the app for a while, or minimize / switch to another window
3. Click the Claude icon on the taskbar to restore the window
4. Window appears completely black — no UI renders

Re-launching from the .exe creates a fresh window that works fine, confirming
the issue is with window restoration, not the app failing to start.

Root Cause (from logs)

The unknown-window.log shows a React hydration error (#418) firing on
nearly every app restore/wake, followed immediately by an EventEmitter memory leak
on the AutoUpdater state store. These errors have been occurring daily since at
least January 18, 2026:

What Should Happen?

When clicking the Claude Desktop icon on the taskbar or restoring the window
from the background, the app should render the UI immediately without a
black/blank screen. The window should reliably restore to its previous state
with the conversation visible, regardless of how long the app has been
minimized or in the background.

What actually happens The window restores but shows a completely black/blank screen. The app process
is running but no UI renders. The only workaround is to fully quit and relaunch
from the .exe file. This happens on the majority of restore attempts,
particularly after the app has been running for a while.

Error Messages/Logs

# From unknown-window.log (recurring on every restore/wake):

[error] Uncaught Error: Minified React error #418; visit https://react.dev/errors/418?args[]=HTML&args[]= for the full message or use the non-minified dev environment for full errors and additional helpful warnings.

[warn] MaxListenersExceededWarning: Possible EventEmitter memory leak detected. 11 $eipc_message$_..._$_claude.web_$_AutoUpdater_$_updaterState_$store$_update listeners added. Use emitter.setMaxListeners() to increase limit

[error] Refused to connect to 'https://a-api.anthropic.com/v1/m' because it violates the following Content Security Policy directive: "connect-src 'self' https://api.segment.io https://*.segment.io https://*.segment.com https://a-cdn.anthropic.com https://*.google.com https://*.facebook.com https://*.facebook.net https://*.doubleclick.net".

[error] Fetch API cannot load https://a-api.anthropic.com/v1/m. Refused to connect because it violates the document's Content Security Policy.

[error] Error sending segment performance metrics TypeError: Failed to fetch

# From main.log (on fresh launch after cache clear, errors returned within minutes):

[error] [REACT_QUERY_CLIENT] QueryClient error: Error: ["account_profile"] data is undefined
[error] ERROR [Statsig] Failed to parse EvaluationResponse

# Timeline showing the error occurs on nearly every startup/restore:
# 2026-01-19, 01-22, 01-23, 01-24, 01-25 (x2), 01-27, 01-28, 01-29, 01-30,
# 02-04, 02-05 (x4), 02-06 (x2) — all React #418 + memory leak warnings

Steps to Reproduce

1. Open Claude Desktop on Windows (v1.1.2156)
2. Use the app normally for any period of time (even a few minutes is enough)
3. Switch to another application, or minimize Claude to the taskbar
4. Click the Claude Desktop icon on the taskbar to restore the window
5. Window appears completely black/blank — no UI content renders

Notes:

• Happens on the majority of restore attempts, not 100% but very frequent
• More likely to occur the longer the app has been running
• Launching fresh from the .exe file always works — the issue is specifically
  with restoring an existing window
• Clearing all app caches allows one clean launch, but the React Feature: implement aider --watch-files #418 error
  returns within minutes and the black window comes back on next restore
• Occurs with and without MCP servers connected

Claude Model

Not sure / Multiple models

Is this a regression?

No, this never worked

Last Working Version

No response

Claude Code Version

2.1.32

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

Other

Additional Information

System Specs

• Windows 11 Build 26200
• AMD Ryzen 9 9950X3D 16-Core Processor
• 128GB RAM
• App version: 1.1.2156 (previously 1.1.1200 and 1.1.351)
• Claude Code: 2.1.32
• Node: 22.21.1 (bundled with app)

Troubleshooting Already Attempted

Full cache clear of the following folders with no lasting fix:

• Cache, Code Cache, GPUCache, DawnGraphiteCache, DawnWebGPUCache
• Session Storage, Local Storage, blob_storage
• window-state.json, Local State, Preferences
• Removed stale app version (app-1.1.1200)

A clean launch succeeds after cache clear, but the React #418 hydration
error returns within minutes and the black window issue resumes on next
window restore.

Key Observations

• The React Feature: implement aider --watch-files #418 error fires on nearly every window restore/wake — logged
  almost daily from Jan 18 to Feb 6 (3 weeks of data)
• Always accompanied by EventEmitter memory leak warnings on the
  AutoUpdater state store (listeners never cleaned up)
• The CSP misconfiguration blocking a-api.anthropic.com/v1/m appears to
  be the app's own analytics endpoint blocked by its own policy
• Issue persists across app versions (1.1.351 → 1.1.1200 → 1.1.2156)
• Launching from the .exe always works — only restoring an existing
  window triggers the black screen

Related Closed Issues

• [BUG] Claude Blank Screen if click minisize button #3592 (Blank screen on minimize - Windows)
• Blank Screen in Claude When Invoking MCP Tools #2230 (Blank screen with MCP tools)
• [BUG] React Hydration Error Prevents Claude Code Web Session Startup #10995 (React hydration error Feature: implement aider --watch-files #418)
• [BUG] Minified React error #418 #11093 (React error Feature: implement aider --watch-files #418 duplicate)

All closed but the underlying problem remains on the latest Windows build.

[jaried]

Additional info: The black screen issue was NOT present in version 2.1.32, but it returned in version 2.1.33. This confirms it's a regression introduced between these two versions.

[pedroreis81]

Sames issue here

[tpabla]

this also happens on mac, and has been an ongoing issue for me for a while, when restarting or updating the page will be blank until resize.

[mmgeorge]

Happening for me as well

[sstklen]

Hey! I ran into a similar pattern in our bug knowledge base and thought this might help.

What's happening: React hydration error #418 occurs because when the Electron window is restored from minimized/background state, the renderer process attempts to rehydrate against stale or empty DOM content. The server-rendered HTML (or previously rendered snapshot) no longer matches the client-side React tree, causing React to bail out of hydration entirely and leaving a blank screen. This is a regression introduced in v2.1.33, likely due to a change in how the Electron BrowserWindow handles visibility restoration — the renderer process may be getting suspended/discarded by Chromium's degreeOfParallelism or background throttling, and the restore path does not trigger a full re-render.

What worked for us:

The Electron renderer needs to detect window restore/visibility-change events and force a full React re-mount instead of attempting hydration against stale DOM. Two approaches: (1) Listen for the 'show' or 'restore' event on BrowserWindow and send an IPC message to the renderer to call root.render() instead of hydrateRoot(), or (2) Add a document visibilitychange listener in the React entry point that forces unmount+remount when the page transitions from hidden to visible with a stale DOM.

Steps:

1. In the Electron main process, add listeners for BrowserWindow 'restore' and 'show' events that send an IPC message (e.g., 'force-rerender') to the renderer
2. In the React entry point (renderer), listen for the 'force-rerender' IPC message and call root.unmount() followed by root = createRoot(container); root.render() to bypass hydration
3. As a safety net, add a document.addEventListener('visibilitychange') handler that checks if document.visibilityState === 'visible' and the DOM container is empty/blank, then trigger the same re-mount logic
4. Consider setting BrowserWindow option backgroundThrottling: false to prevent Chromium from aggressively suspending the renderer process when minimized
5. Investigate what changed between v2.1.32 and v2.1.33 — likely a React upgrade from renderToString to server components, or a change in the Electron BrowserWindow webPreferences that enabled more aggressive background throttling

// Main process (main.ts)
mainWindow.on('restore', () => {
  mainWindow.webContents.send('force-rerender');
});
mainWindow.on('show', () => {
  mainWindow.webContents.send('force-rerender');
});

// Renderer entry (index.tsx)
import { ipcRenderer } from 'electron';

let root = hydrateRoot(container, <App />);

ipcRenderer.on('force-rerender', () => {
  root.unmount();
  root = createRoot(container);
  root.render(<App />);
});

// Fallback: visibilitychange listener
document.addEventListener('visibilitychange', () => {
  if (document.visibilityState === 'visible' && container.childElementCount === 0) {
    root.unmount();
    root = createRoot(container);
    root.render(<App />);
  }
});

// BrowserWindow options — prevent renderer suspension
const mainWindow = new BrowserWindow({
  backgroundThrottling: false,
  // ... other options
});

📊 We found 1 similar case in our knowledge base with the same pattern — this gives us medium confidence in this analysis.

Hope this helps! Let me know if it doesn't match your case — happy to dig deeper. 🦞

Disclosure: This analysis is from Confucius Debug, an AI-powered community KB for agent bugs. Please verify before applying.

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