I-Firefox Community Forum

Windows11，firefox版本149.0，增强型跟踪保护设置为标准，基于 HTTPS 的 DNS”启用策略为默认保护，扩展全关。在我打开www.douyin.com的标签页时，通常要加载5秒钟甚至10秒钟，视频才会播放（如图）。作为对比，我在edge浏览器上登陆了同一个抖音账号，打开同样的书签页面，edge并未出现明显加载画面，在chrome上打开未登陆的抖音标签页也未出现明显加载画面。这个情况也许是从近期firefox自动更新后出现的？请问如何解决

My current version of Firefox is 151.0.4 (64-bit) & for the past 2 weeks or so every time I use the search bar to google something it triggers one of those "We've detected unusual activity from your network" requiring a Captcha. At first I tried all of the typical stuff [antivirus, vpn, extensions, etc...] to make sure that wasn't the issue. But as of yesterday & confirmed today I can actually go to Google's website first & do the search from there with no issue & no captcha.

So, whatever the issue is has to do specifically with doing the search via the search bar... for some reason. Is this a bug in the browser, or is there perhaps some setting that could cause this to happen in the about:config page? Though, I doubt a setting could be it because I've changed the settings I've changed now for years without causing this issue.

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?

My bookmarks have stopped working. When I went to Edit Bookmark I found they are all empty. I can create a new bookmark as usual, but I have over 300 bookmarks that no long function that are very important to my work. Is there any way I can possibly restore them, as my work depends on them?

I have a problem with 'efficiency mode' in Windows 11. Windows 11 forcefully puts many of Firefox's tasks into efficiency mode marked by green leaves within task manager in processes tab. It doesn't seem to do this to anything else except Steam Client WebHelper. My Laptop is always in max performance mode in all possible settings as it is always plugged in (this does not influence efficiency mode). It slows down performance making things take longer to load and might even break them. If you try to enable efficiency mode on a task it even warns you of this: 'Efficiency mode will lower process priority and improve power efficiency but may cause instability for certain processes. Do you want to continue?' There is no way to permanently disable it. Currently out of 19 tasks 8 are in efficiency after I woke up my laptop from sleep (I have 5 tabs open). Only way to stop it is to manually disable each one by one (right click on each task and disable efficiency mode). But Windows 11 will turn them back on automatically usually within a few seconds (it seems to depend on opening new tabs, reloading them or waking up the PC from sleep mode). From looking it up online there seems to be a way to disable it in browser on Edge and Chrome but that might be something else (I do not use the so I'm not sure). There was a solution for Chrome but it doesn't work on Firefox.

Is there any way this can be disabled permanently through Firefox or Windows 11?

Hello, I am experiencing an issue where the built-in Firefox VPN feature has completely disappeared from my browser interface. I cannot see the icon on the toolbar, and the feature is not active. Could you please clarify if this feature has been geo-restricted or temporarily disabled for certain regions, or if there is another hidden preference I need to modify to restore it? Thank you for your assistance.

(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?

For the last 2-3 day I have been experiencing a box that asks for my signature each time I go to a new website. I can't move the box. I can't screenshot it. Does anyone know how I can get rid of it?

I'm trying to add the world cup tracker to my home screen, but when i click the link, it just puts me in my new tab page with no changes. When I click the pencil edit icon, widgets are not an option for me. Is there a place I need to enable them?

Issue persists on Incognito Mode and it goes away if I use different browser.

Since 2 days issue like this happened and it is retroactive meaning all previous conversations are also blank, all replies of chatgpt are blank except replies with image generation, those are fine.

Before you recommend me to do something please keep in mind that Incognito itself does not help.

I am able to share that chat, paste it in my firefox and page is blank. https://chatgpt.com/s/t_69f4b354cc188191a7959c2d443fed9d

I can use this adress on different browser and it works fine

From Firefox, I have launched Earthlink Web Mail. When reading an email, scrolling doesn't work. It worked yesterday from firefox. It works today on Edge. It works today on my Android phone.

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.

After today (Sep. 2, 2026)'s update, I noticed that the the plus "+" button for new tab is canceled. Instead, I have to now click right on the work function and click "New Tab" for a new tab. This revision is quite counter-intuitive. Could you please add back the plus "+" button for new tab in the next update?

Thank you very much.

Hi, I'm running FF 149.0 (64-bit) on Windows 11. I've used profiles for a while now and on several occassions I've "lost profiles". Currently I have three profiles which I set up and edited the icon and colour associated with each. When I launch FF I see the Profile Manager and can select any of the three and I can create a new profile which shows here. However, once in any one of the FF profiles I don't see the others - by which I mean that when I go via the hamburger lines top right and click on the current profile, the 'other profiles' section is blank. I also cannot edit the profile from using the edit pencil top right (after clicking the hamburger lines and clicking on the current profile), it takes me to about:editprofile but the page is completely blank. Confusingly, if I go to about:profiles I see two profiles, neither of which shows up in the Profile Manager! I'm going round in circles trying to understand where to edit my exisitng profiles and make sense of the five profiles that don't all show up in the same place!