2011099 - Firefox renders completely blank UI (about:home/new tab) on KDE with NVIDIA — affects both Wayland and X11

Status: RESOLVED INCOMPLETE

(Core :: Widget: Gtk, enhancement)

Description

[tina-rene]

Attachment: firefox_version.txt

User Agent: Mozilla/5.0 (X11; Linux x86_64; rv:147.0) Gecko/20100101 Firefox/147.0

Steps to reproduce:

1. Start Firefox normally.
2. Observe the start page (about:home).
3. Result: completely blank white window, no UI elements, no search box, no tiles.
4. Open a new tab -> also blank.
5. Navigate manually to about:home -> still blank.
6. Repeat the same test under Plasma (X11) → still blank.

Actual results:

Firefox opens with a completely blank window. The browser process is running and tabs
exist, but nothing is rendered in the UI.

about:home and all new tabs are entirely empty (white/blank), showing no search bar,
no tiles, no toolbar content inside the page, and no visual UI elements of the start page.

This behavior occurs consistently:

• with a brand-new profile,
• after a Firefox Refresh,
• with all extensions and themes disabled,
• and in both KDE Wayland and KDE X11 sessions.

External websites may sometimes render if manually typed into the address bar, but
Firefox’s internal pages (about:home, new tab) remain permanently blank.

Expected results:

Firefox should display the normal start page when opening a new window or new tab.

about:home should render correctly, including:

• the central search bar,
• pinned and recent site tiles,
• optional widgets (e.g., weather),
• and all normal UI elements of the new-tab page.

New tabs should load the standard Firefox new-tab layout rather than appearing blank.

This behavior should be consistent across both KDE Wayland and KDE X11 sessions.

Comment 1

[BugBot [:suhaib / :marco]]

The Bugbug bot thinks this bug should belong to the 'Core::Widget: Gtk' component, and is moving the bug to that component. Please correct in case you think the bot is wrong.

Comment 2

[Martin Stránský [:stransky] (ni? me)]

Please try latest nightly from upstream:
https://fedoraproject.org/wiki/How_to_debug_Firefox_problems#Testing_Mozilla_Nightly_binaries
and also try safe mode:
https://support.mozilla.org/en-US/kb/diagnose-firefox-issues-using-troubleshoot-mode#w_start-firefox-in-troubleshoot-mode
Thanks.

Comment 3

[tina-rene]

Attachment: firefox-146.log.moz_log

Comment 4

[tina-rene]

Attachment: firefox-147-flatpak-console.log

Comment 5

[tina-rene]

Attachment: firefox-149-nightly-console.log

Comment 6

[tina-rene]

Thanks — here are the requested test results.

I tested the versions you suggested:

Results:

• Firefox 146.0.1 (Arch package): WORKS

  • Starts and renders the UI normally.
  • Debug log attached: firefox-146.log

• Firefox 147.0.1 (Flatpak: org.mozilla.firefox): BROKEN

  • The main window appears blank/black after startup.
  • Process runs, but no UI is rendered.
  • Console output attached: firefox-147-flatpak.log

• Firefox Nightly 149.0a1 (upstream tarball): WORKS

  • Starts and renders correctly, no blank screen observed.
  • Debug log attached: firefox-149-nightly.log

Environment:

• Distribution: CachyOS (Arch-based)
• Kernel: 6.12.66-2-cachyos-lts
• GPU: NVIDIA (Driver 550.163.01, X11 session)
• Session type: X11

These results suggest that a regression occurred in the 147, since version 146 is unaffected and the issue is resolved in Nightly 149.

Let me know if additional logs or tests (e.g., ESR, Wayland) are needed.

Flags: needinfo-

Comment 7

[Martin Stránský [:stransky] (ni? me)]

If 147.0 is affected only, can you try mozregression to find the broken commit?
https://fedoraproject.org/wiki/How_to_debug_Firefox_problems#Use_Mozregression_tool
Thanks.

Comment 8

[BugBot [:suhaib / :marco]]

Redirect a needinfo that is pending on an inactive user to the triage owner.
:stransky, could you please find another way to get the information or close the bug as INCOMPLETE if it is not actionable?

For more information, please visit BugBot documentation.