Linux: main window renders 100% blank on fresh profile — page loads without errors (Desktop 2.7032.0, Ubuntu, AMD Cezanne)

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?

Claude Desktop for Linux opens to a window that is entirely blank — a uniform dark fill, no UI ever painted. The app process is alive and the claude.ai login page loads and runs its scripts, but none of its pixels reach the window.

Objective proof it is a flat fill: captured the window with ImageMagick import and ran a color histogram. 99.99% of pixels are near-black (#131313); the only non-dark pixels (0.007%) are the title-bar buttons. No login form is drawn.
[3-space indent] window id: 20971524
[3-space indent] 1035956: (19.4553,19.4553,19.4553)
#131313
[3-space indent] 1312: (35,35,34)
#232322
[3-space indent] 48: (194,192,182)
#C2C0B6
[3-space indent] 24: (99,98,94)
#63635E
[3-space indent] 4: (152,151,142)
#99988F
→ dark 99.993%, UI pixels 0.0073%

The web view is loading fine — claude.ai-web.log and the Chromium console both show the login page loading and running (hcaptcha preload, Permissions-Policy feature warnings, all sourced from https://claude.ai/login). There is no crash, no "render process gone", no EGL/GBM failure anywhere in the logs.

This is not a system issue: VS Code and other Electron apps render perfectly in the same session.

Things that do NOT fix it: --disable-gpu, --ozone-platform=x11, hiding the Wayland socket (env -u WAYLAND_DISPLAY), full wipe of ~/.config/Claude, and apt purge + reinstall.

What Should Happen?

The main window should paint the claude.ai login page (and after sign-in, the app UI) instead of a uniform blank fill.

Error Messages/Logs

No crash or fatal errors. Only benign lines while the window stays blank:

[ERROR:ui/gl/gl_surface_presentation_helper.cc:260] GetVSyncParametersIfAvailable() failed for 1 times! (and 2, 3)
[WARNING:sandbox/policy/linux/sandbox_linux.cc:405] InitializeSandbox() called with multiple threads in process gpu-process.
[WARNING:ui/aura/window.cc:1456] StackChildLayerRelativeTo called with unmanaged layer(s). child=WebContentsViewAura
[INFO:CONSOLE] "Error with Permissions-Policy header: Unrecognized feature: 'attribution-reporting'." source: (0)
[INFO:CONSOLE] hcaptcha api.js preloaded but not used within a few seconds — source: https://claude.ai/login (0)

main.log shows repeated clean "Starting app" entries and a loop of "[account] Account details not yet available, waiting for IPC..." (expected — no one is signed in because the login form never paints).

Steps to Reproduce

1. Install Claude Desktop on Ubuntu from Anthropic's apt repo.
2. Run: sudo update-desktop-database /usr/share/applications (needed for deep-link sign-in).
3. Launch: claude-desktop
4. Window opens as a uniform dark rectangle; no login UI is ever drawn.
5. Confirm objectively:

W=$(xdotool search --name "Claude" | tail -1)
import -window "$W" ~/claude-shot.png
convert ~/claude-shot.png -colors 8 -format '%c' histogram:info: | sort -rn | head
→ ~99.99% of pixels are #131313.

Persists across a full profile wipe (rm -rf ~/.config/Claude) and apt purge + reinstall.

Claude Model

None

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

Claude Desktop 2.7032.0 (Linux).

Platform

Anthropic API

Operating System

Ubuntu/Debian Linux

Terminal/Shell

PowerShell

Additional Information

• OS: Ubuntu (resolute/25.10-class), GNOME, session=wayland
• GPU: AMD Cezanne (Radeon Vega, integrated), Mesa open-source driver
• Claude Desktop: 2.7032.0, installed from Anthropic's apt repo
• Same blank result whether launched native-Wayland or with --ozone-platform=x11
• VS Code (Electron) renders fine in the same session, so this is app-specific

Attaching: main.log, claude.ai-web.log, and claude-shot.png (the blank window capture).

main.log

<img width="1232" height="842" alt="Image" src="https://github.com/user-attachments/assets/5f2530be-6d91-4f19-9212-07227a611a78" />

claude.ai-web.log