Firefox Community Forum

I view a lot of pdf documents via firefox, the light gray background makes my eyes and head hurt after prolonged usage. In the past I found a solution on this forum that advised to set pdfjs.viewerCssTheme to "2" in about:config. This set the background of pdf viewer to black/dark gray. This has worked for years until recently when the pdf viewer switched to light mode again (pic 1). I checked the about:config settings for pdfjs.viewerCssTheme but there appears to be no change. I tried restarting the browser, setting the theme to 0 and to 2 again, updating browser. Sadly the theme is still light gray. Is there a way to change it again? The desired outcome is in pic 2. I do NOT want to change the color of the pdf pages themselves.

I'd like to add Firefox to Adobe Dreamweaver for site design viewing. When searching Windows for Firefox.exe I don't see it in Program Files or Program Files (x86). Firefox is installed and used daily. Can someone tell me where it's located in Windows 10?

Hello,

I dislike the Group Tabs feature. So many times I've accidentally created a Group Tab and then had to figure out how to un-group them.

I've tried to change the value of the "browser.tabs.groups.enabled" preference to false, but it doesn't stick; after restarting, the value is always back to "true".

What’s up with this?

Thanks, Andre’a

A recent set of system updates appears to have made most website videos not play in Firefox.

When I inspect the Developer Tools - > Console tab the most detail Firefox gives are an error line similar to: Media resource URL could not be decoded, error: Error Code: NS_ERROR_DOM_MEDIA_METADATA_ERR (0x806e0006)

Internet searches for the error name and error hex do not appear yield any applicable troubleshooting, nor any methods of collecting additional problem data.

How can I obtain more detail on where the error is happening and how Firefox might be interacting with other packages present on my system?

Arch Linux has some older ffmpeg-compat packages, but those don't appear to match any of the web results, in that they're even older versions of ffmpeg.

yay -Ss ffmpeg-compat aur/ffmpeg-compat-55 2.3.6-4 (+24 0.00)

   Compatibility package for ffmpeg to provide versions 55 of libavcodec, libavdevice and libavformat, not anymore provided by the ffmpeg package

aur/ffmpeg-compat-54 1.2.12-4 (+87 0.00)

   Compatibility package for ffmpeg to provide versions 54 of libavcodec, libavdevice and libavformat, not anymore provided by the ffmpeg package

Today for the first time after the latest update 127.0 (64-bit), my many firefox pages and tabs crashed and closed and a pop up to send crash report.

So I have fired up firefox again to find only a single page opens up, I have lost probably 16+ pages with multiple tabs on each, been like that for months, I have 32GB memory so there is normally no issues or slowness. However after the crash, even though only a single firefox page is open, windows task manager shows Firefox (20) and if I expand the task, I can see each firefox is taking lots of memory.

So it looks like the old session pages/tabs are still there somewhere but not accessible, I would like to get them back if possible. I went through reseting it to default, disabling the add ons etc but nothing has worked.

When I'm in full screen mode, The Apple, "Firefox" "File" "Edit" "View" "History" "Bookmarks" "Tools" etc menu bar shows up at the top and won't disappear. On my iMac Pro, it doesn't show up. i.e. Off.

I can't figure out what is the setting to make sure it does not appear. I went digging everywhere and can't figure it out. If you could tell me what config, etc I'm missing I'd appreciate it.

Screen shot attached to show which menu bar I mean.

My firefox is up to date: 126.0 (64-bit)

Hi, I've upgraded to Windows 11 today and couldn't open Firefox since. Things I've already tried:

• Reinstall Firefox and delete all old files (Appdata & Program files)
• sfc /scannow and DISM.exe /Online /Cleanup-image /Restorehealth
• Windows compatibilty mode
• Firefox Troubleshoot mode won't open either
• ipconfig /release & /flushdns & /renew
• netsh int ip reset & netsh winsock reset

When opening Firefox in any way, i get a white window/just the window border which immediatly closes. When trying to start troubleshoot mode, the small window has the same issue.

I also checked the crashlogs and none were generated. The Windows event-logger also has no entries.

BTW: Here is a video of whats happening: https://youtu.be/AJP4rqZFxlY

I have no idea what to do - send help please.

The bookmarks icons and fonts are too small for my older eyes on my new Ubuntu computer. They are bigger on my older Ubuntu computer. I have tried to find out how to enlarge them without sussex.

I am aware of the Zoom feature for a webpage itself, I am not asking about that. I simply want to have my bookmark toolbar FONTS and ICONS larger.

This has been frustrating. Perhaps including an EASY way to do this for future updates, or an app suggestion that would solve the problem. Thanks for your consideration and (hopefully) help.

I've just switched to firefox from brave, and theres no button on twitch to enable picture in picture. Using the keyboard shortcut (cmd+option+shift+]) works, but I'd much rather click something on the screen. On brave there used to be a picture in picture button alongside settings, theatre mode, and fullscreen buttons, but on firefox this has been replaced by a clip button. There's no option for it if I right click (this works on youtube), and no option in the address bar for either twitch or youtube. I've tried disabling all my extensions and lowering protections but nothing seems to work.

Firefox now requires me to use a passkey to log in to YouTube. I don't have (or want) a passkey. My computer locks up solid, and I have to reboot when I cancel the request for a passkey. I can log in to YouTube on my Samsung S10+ tablet and S25 phone without problems. This problem only occurs on my Windows 10 computer. It is impossible to bypass this issue.

Automatically hide taskbar in desktop mode => Enabled Firefox => Maximised When cursor is moved to outer edge of screen, taskbar should unhide (Expected behaviour) but in this case it remain hidden (Reality). Firefox along with all other spinoffs give same result. Chromium based browser works perfect, and taskbar automatically unhide itself.

As OLED screen have became common as monitor, Taskbar auto-hide is must. If this issue cann't be fixed I may have to change my primary browser which I used for almost 15 years.

Kindly, look into it. If Chromium can do it, why not Firefox.

I always set Firefox to open the previous sessions tabs when starting. For some reason during the start up over the past several days Firefox opens to the home page only. I then have to search the history to find the closed tabs. Except for this problem, Firefox is working perfectly.

Does anyone have any suggestions as to why this is going wrong and a possible way to fix it?

Hi, not sure what I'm doing wrong, but my logins and passwords simply will not synch between devices. I principally use a desktop Win10 machine, and an iOS version of Firefox. Have double-checked settings on both devices, tried forcing a manual sync from each to the other, all to no avail. Any ideas on what I need to do differently? TIA.

Today a website told me I needed to enable JavaScript in order to continue, despite the fact that it is enabled. At first, when I received this message, I turned off the "NoScript" extension and tried again, but the website still gave me that same message. So then I went to the about:config page. and it showed that JavaScript is enabled because it showed a value of "true". This sort of thing has happened more than once in the past. I'm forced to go to another browser such Microsoft Edge or Chrome, where I do not encounter this problem. Why is this happening in Firefox, and what can I do about it? My operating system is Windows 10 Professional, and if you need any other details, please let me know. I will appreciate your assistance.

From the subject line - I keep getting this error when trying to use Firefox Sync on my Windows 10 desktop. Sync already works on Mac and Android, and I've already verified that I'm using my primary email to login.

When streaming a video and using PiP, after opening another window or program and then pausing said video that is currently being played on the PiP player window, sometimes this causes the actual video itself being played via the PiP player window to freeze. So the video is paused and I want to resume play but when clicking the 'play' button on the PiP player window the video refuses to play.

The only way to clear this bug is to click the 'close' button or the 'back to tab' button on the PiP player window and then refresh the actual web page. After refreshing the web page and repeating the same steps - the PiP player window works just fine with playing and pausing, but it's annoying that I have to do this.

ATT.NET is blocking my access to ATT/Yahoo email from my ATT.net account using Firefox ''but not using Chrome?'' I have stopped all tracking and cookie blocking

"Something's gone wrong We may be having trouble with your connection. Connecting your device to Wi-Fi could help fix the issue or try again later. If you were using an app, close this page. Otherwise, start over."

This is a silly one, probably.

My refresh button has mysteriously disappeared from my browser toolbar. I can just use cmd+shift+r to refresh, but muscle memory keeps looking for the button on screen too, and it would be nice to have it back!

I opened up the customize options, thinking maybe I just removed it by accident, but refresh doesn't appear to be an option?

I also opened it up in troubleshoot mode to see if that would change anything. It did not :(

I also don't have any extensions that mess with the toolbar, so I don't think that would be an issue (and troubleshoot mode should have disabled extensions anyway I think.)

I recently updated to 126.0.1 - no idea if that has anything to do with it, but this did happen right after the update.

There are a couple more people on here with the same question, and they all had easy solutions. I'm hoping I'm just not seeing a setting somewhere.

Thanks!

I have a very good PC (5800X3D, 7900XT, 32GB DDR4 3600), but Firefox (either the normal, canary and nightly version) can't play smoothly any 4K video (like the Borderlands trailer: https://www.youtube.com/watch?v=lU_NKNZljoQ ). 1440 and lower resolutions are fine, as are 4K videos on Chrome and Edge. FWIW, my CPU during 4K playback is barely used (1-2%), and my GPU's video codec (VCE) is used by around a third. Disabling HW accel makes things better, as it still stutters but it's (barely) passable. I already tried creating a new profile, but still it's the same.