Firefox Community Forum

Firefox 146.0.1 crashes every time upon launch (basically fails to launch), even in troubleshooting mode, with exception code 0xc0000005. Prior to today, it was working fine. Windows does not show any updates made over the last couple of days. I am on Windows 11 25H2, and I'm current with updates. Chrome works. Edge works. I logged on to the same computer as a different user (different profile folder in the user AppData folder) and Firefox still does not work. I tried to refresh Firefox and that did not resolve the issue. I tried to uninstall and reinstall Firefox and that did not resolve the issue. I tried to run DISM and SCANNOW and that did not resolve the issue. No issues are detected with a virus scan. I am stumped - please help!

In Firefox version 149, there is an issue with print preview behavior for HTML <select> elements. When opening print preview, all <option> items inside a dropdown are displayed and included in the print output.

This behavior differs from Firefox 148, where only the selected option is rendered correctly during print preview.

Steps to reproduce:

- Create an HTML page with a <select> dropdown containing multiple <option> elements. - Select one of the options. - Open print preview (Ctrl + P).

Expected result: Only the selected option should be visible and printed.

Actual result: All options inside the <select> element are displayed and printed.

Impact: This issue breaks the layout of printed documents and makes forms difficult to read, especially when dropdowns contain many options.

Things like, "set firefox as your default browser" and "open firefox when you start your computer?".

I don't want pop-ups from ANYBODY, but especially not from the browser. It defeats the whole purpose of blocking pop-ups if the browser itself is interrupting me with garbage I dont need.

How do I turn these off? There don't appear to be any settings, and every google search brings up disabling pop-ups for every other site.

Hello,

I would like to obtain the complete release history of Firefox ESR Portable, including:

The exact release date of each Firefox ESR Portable version. The corresponding Firefox ESR version number (e.g., 115.x ESR, 128.x ESR, 140.x ESR, etc.). Any available information regarding delays between the release of Firefox ESR by Mozilla and the release of Firefox ESR Portable.

Could you please provide a list of all Firefox ESR Portable releases along with their release dates, or direct me to an official source where this information can be found?

Thank you for your assistance.

Hello, I've been using Firefox for several years because of all browsers it's the only one (I know of) that has a setting whether to open links in new tab or in new window. I want them opening in tabs. This has been quite alright until last week when I was suddenly shown a message that I was using an old Firefox version and was forced to create a new profile. I did that but ever since then links keep opening in new windows - even though I have found the relevant setting and ticked the box "Open links in tabs instead of new windows". With or without the box ticked, the only way to open links in new tabs is to simultaneously hold Cttrl and click on the link. I've tried all variations of this box and the next two, but no luck. This is really important for me. What am I doing wrong? Thanks!

Images have not been displaying properly. Or when they display properly, the images may go blank when scrolling past them or hovering the cursor over them. This is specifically troublesome with buttons to click on to confirm "yes" or "no", "next" or "start" where the text within those buttons is not visible. I've included a screen shot showing how some of the images appear on screen. Thank you for any suggestions you may have.

Постоянное отображение панели задач (до тех пор, пока не нажму на иконку браузера на панели дважды. Повторяется с каждым заходом в режим "на весь экран" ), при просмотре видео, в браузере, в формате "на весь экран" с версии 156.0. в других браузерах подобной проблемы нет, только в Firefox. Прикладываю скрин визуального отображения проблемы. С настройками самой панели задач проблем нет, перепроверял.

I downloaded Firefox today and saw there was a VPN option but it is not working. It asks me to sign in and per the instructions the clickable icon at the top should now have an option to enable but it just asks me to sign in again. I am from Canada and it says my region is available for this program.

I have an website which I prior to this error message have visited many times on Firefox and had no problems. Recently though around two days ago I noticed that I couldn't get in and was met with the following message "Warning: Potential Security Risk Ahead". I can't bypass it apparently and I really need to be able to access this site as it's a University site.

I can access the site on other browsers such as Chrome and Edge but I use Firefox as my default browser and I'd like to keep it that way. I'd appreciate any help I can get.

Said link: https://canvas.gu.se/

(AI written summary of troubleshooting steps taken before making this support thread)

Firefox version: - 152.0.1 Release - 153.0 Nightly

OS: - Windows 11 build 26200

GPU: - NVIDIA GeForce RTX 4070 SUPER

Codec package: - Microsoft HEVC Video Extensions installed from Microsoft Store

Problem

Firefox does not expose HEVC playback support, causing Twitch to disable 1440p streams encoded with HEVC.

The same machine can play the same HEVC Twitch streams in Chrome immediately after installing HEVC Video Extensions.

Expected result

Firefox should report HEVC playback support and allow playback of HEVC streams, as Chrome does on the same system.

Actual result

Firefox reports HEVC as unsupported.

about:support:

codecSupportInfo: H264 SWDEC HWDEC VP9 SWDEC HWDEC VP8 SWDEC HWDEC AV1 SWDEC HWDEC HEVC NONE

Troubleshooting already performed

- Installed Microsoft HEVC Video Extensions - Rebooted Windows - Updated NVIDIA drivers - Verified hardware acceleration is enabled - Tested with a brand new Firefox profile - Tested with Firefox Nightly - Confirmed Chrome can play the same HEVC streams

Additional observations

Chrome: - Twitch 1440p becomes available immediately after installing HEVC Video Extensions - Twitch Stats for Nerds reports:

 hev1.1.6.L150.90.0.0.0.0.0

Firefox: - Twitch reports that the browser does not support the required resolution - 1440p remains greyed out - about:support continues to report HEVC NONE

Reproducible tests

Firefox console:

MediaSource.isTypeSupported('video/mp4; codecs="hev1.1.6.L150.90"')

Result: false

MediaSource.isTypeSupported('video/mp4; codecs="hvc1.1.6.L150.90"')

Result: false

navigator.mediaCapabilities.decodingInfo({

 type: "media-source",
 video: {
   contentType: 'video/mp4; codecs="hev1.1.6.L150.90"',
   width: 2560,
   height: 1440,
   bitrate: 8000000,
   framerate: 60
 }

})

Result: {

 supported: false,
 smooth: false,
 powerEfficient: false

}

For comparison:

MediaSource.isTypeSupported('video/mp4; codecs="av01.0.08M.08"')

Result: true

navigator.mediaCapabilities.decodingInfo({

 type: "file",
 video: {
   contentType: 'video/mp4; codecs="av01.0.08M.08"',
   width: 2560,
   height: 1440,
   bitrate: 8000000,
   framerate: 60
 }

})

Result: {

 supported: true,
 smooth: true,
 powerEfficient: true

}

Additional note

Setting:

dom.media.webcodecs.h265.enabled = true

causes HTML5 codec test (https://html5test.co/) to report H.265 support, but does not change:

- about:support - MediaSource.isTypeSupported() - MediaCapabilities.decodingInfo() - Twitch HEVC playback availability

Question

Is this a known issue with HEVC Media Source Extensions support on Windows 11 build 26200, or is there another requirement for Firefox to expose HEVC playback capability through MediaSource and MediaCapabilities when the Windows HEVC codec is installed and functioning in Chromium-based browsers?

Hi. Now that the 'Open Link in Split View' has annoyingly replaced the spot previously held by 'Open Link in New Window' i keep clicking on it accidentally (muscle memory).

I don't want to have to retrain my muscle memory, but despite creating css file generated by Claude that should in theory remove the option, and putting it the Profile Folder, it will not go away.

How do i remove it?

Running on Windows 11. There are many supposed "solutions" on the Web, but none of them work. I have tried with: about:config, css files, etc. None of them work.

I like Firefox greatly, but this is so frustrating.

The developers have created a solution to a problem that didn't exist. The result is to make Firefox user clumsy.

It would have been nice if they - at the very least - had provided a way to change the 'Profiles' icon position on the menu.

Again, Firefox 153.0.1 (64-bit) on up-to-date Windows 11. Amd Ryzen 5, 6 core processor, 32 GB Ram, 500 GB SSD C drive = 197 GB free.

My VPN used to work perfectly with my South African sites. Since I've downloaded the new Beta version of Firefox, things have become unstable, and the South African sites - mainly my dictionaries (which I use daily because I'm a translator) - don't work any more.

South Africa is one of the countries on the list, but when I open the VPN now, it says South Africa is unavailable, which had never been the case before.

Please help me sort it out. I can't take screenshots of the problem. When I go to the country list from the VPN, the dialogue box disappears.

Firefox 152.0.3 on Windows 10. SVG icons such as Google Maps interstate shields flash briefly then turn into squiggly lines. Same issue occurs when uploading images to websites and viewing Amazon book previews. Works fine in Chrome. Already tried: disabling hardware acceleration, toggling gfx.webrender.all, gfx.webrender.software.d3d11, gfx.webrender.allow-partial-present-buffer-age in about:config, clearing startup cache, removing Tampermonkey extension, disabling Killer Network Manager (CNMNSST.exe). I uploaded an image of how interstate icons show up in google maps.

I went to [https://support.mozilla.org/en-US/kb/firefox-backup] and under "Create a Firefox backup file" at step 3 it says, "Scroll down to Backup, and click Manage backup" but when I went there no such "Manage backup" option exists as you can see in the attached screen capture. So what gives? How can I "Create a Firefox backup file"? I am using Firefox v147.0 (64-bit) on Windows 11 Please instruct. Thanks RJB

I read the article about having 50 GB of free VPN use after I updated Firefox today to version 149.0; however, I don't see anywhere where I can enable the VPN. I've checked in the "Customize Toolbar" section, and I still couldn't find anything. I don't understand, the article made it sound like I should have access, but I've also read that it's not out for everyone yet?

I just opened Firefox on my Win 11 pc, and find all my tabs have gone. The setting to reopen last session is active, as before. I think FF updated itself earlier today. I also had occasion to look at it briefly on my synchronised android phone. I would like to: - get my tabs back - find a way to stop this haappening (it's not the first time).

Any advice much appreciated, thanks. Richard