Mozilla has released an emergency update to fix a display issue affecting Firefox users with Nvidia graphics cards. The bug, introduced in Firefox version 139.0, causes visual glitches on multi-monitor setups with different refresh rates.
What’s the Problem?
The issue appears when 60 FPS media is played on a secondary monitor, while the main display runs at a higher refresh rate—typically 144 Hz. Users have reported graphical artifacts and screen tearing on the primary display.
The root cause is linked to a recent change in Firefox. Mozilla had disabled a blocklist that previously prevented DirectComposition from being used with Nvidia GPUs. While the change aimed to improve performance, it unintentionally triggered rendering issues under certain conditions.
Who’s Affected?
This bug only affects users with:
- Nvidia GPUs
- Multi-monitor setups
- Displays running at mismatched refresh rates (e.g. 144 Hz and 60 Hz)
If you’re using a single monitor, or have Intel or AMD graphics, you won’t be impacted.
The Fix: Firefox 139.0.1
Mozilla has rolled out Firefox version 139.0.1 to address the issue. This update doesn’t add new features—it’s purely a bug fix.
To update your browser:
- Click the menu button (☰)
- Go to Help > About Firefox
- Firefox will check for updates and install version 139.0.1 automatically
If you can’t update right away, you can apply a temporary workaround:
- Type
about:configin the address bar - Search for
gfx.webrender.dcomp-video-hw-overlay-win - Set it to
false
This disables a feature that contributes to the artifacting, offering a short-term fix until you can update.
Where to Get the Update
You can download the latest version of Firefox directly from Mozilla’s official site.
It’s a good idea to stay on top of browser updates, especially when they address hardware-specific bugs like this one.
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Original source: Tom’s Hardware








