Komunitné fórum Firefox

I am a Cacti developer and we are considering switching from FontAwesome Web Fonts to Tabler Web Fonts. However, on Firefox for Windows only, we are having a major slowdown when using the Tabler SVG based webfonts. The page load is first stalled by Firefox apparently loading all the Web Fonts, which would appear normal with any browser (though exceedingly slow on Firefox for some reason).

However, once the page is loaded, when going off tab to another browser tab, and then back to the Firefox tab that includes the Tabler webfonts, there is a 3 second delay before the tab switches. When we enable the performance analyzer, we find that the delay is almost 100% Reflow of the page, even though the page is static as this point (no changes) from the last time it was activated.

We do not have this issue on Firefox for Linux, MS Edge or any other Chromium browser, only Firefox on Windows. I'm using the latest version 134. Should I be opening a bug?

I had a problem where FF 140.0 would not update, and in trying to get FF yo update, I used a re-install tool to which I was pointed in my problem report. This caused FF to wipe out my configuration, and I lost all my windows and tabs. I have gone to

    \Appdata\Roaming\Mozilla\Firefox\Proifiles\abnfpged.default

cleared all of the data therein, and restored that directory from a backup I made last Monday. But I cannot get FF to use that directory. "about:profiles" shows only two profiles, but the Profiles directory has five profiles:

03/10/2026 09:39 AM <DIR> qf00ka5x.default 03/10/2026 09:39 AM <DIR> v842ceue.default-release 04/11/2026 09:16 PM <DIR> .. 04/11/2026 09:16 PM <DIR> . 04/12/2026 03:08 PM <DIR> abnfpged.default 04/12/2026 06:29 PM <DIR> jdfj91sd.default-release-1775960183850 04/12/2026 06:48 PM <DIR> f1jq4mlq.default

Only the profiles beginning with "j" and "f1" are seen in the "about:profiles" screenshot I have attached. And I have attached a screenshot of my profiles.ini file. Also, in the abnfpged.default directory I restored, where is the list of all of my open windows and tabs? FF used to keep that in a sessionstore.jsonlz4 file, but that file is only written when FF closes. I tried to save a copy when I was having problems, but I stored the copy in the same directory, which FF changed during the re-install process. Here is my profiles,.ini file:

[Install308046B0AF4A39CB] Default=Profiles/jdfj91sd.default-release-1775960183850 Locked=1

[Profile1] Name=default IsRelative=1 Path=Profiles/f1jq4mlq.default

[Profile0] Name=default-release IsRelative=1 Path=Profiles/jdfj91sd.default-release-1775960183850

[Install641D10338ABA448D] Default=Profiles/abnfpged.default Default=1 IsRelative=1 Locked=1

[General]

StartWithLastProfile=1

Version=2

[BackgroundTasksProfiles] MozillaBackgroundTask-308046B0AF4A39CB-defaultagent=lnvi5jn5.MozillaBackgroundTask-308046B0AF4A39CB-defaultagent

I have not worked with the ;profiles.ini file in many years, as my FF configuration has not had problems. Thanks.

I've freshly reinstalled Windows 11 and after trying to access and watch a movie on any of these sites I get an error (see the pictures).

Browser version: 137.0.1 (64 bit) Widevine version: 4.10.2891.0

Already tried to disable/enable DRM. Already reinstalled firefox. Already manually installed widevine. No clue what could be causing this issue.

I upgraded my version of Firefox from an ESR version to v129.0.1 on Debian 12. Drag and drop of files from the desktop or the file manager (PCManFM-Qt) into the browser stopped working. It is still working properly in Chrome.

This occurs with several web apps but, as an example, it occurs when trying to drag a jpeg into Roundcube Webmail while composing a message.

No browser console errors are genrated when trying to do this. It occurs in Troubleshooting (safe) mode as well. In apps that pop-up a "Drag files here" target, that target still appears but dropping the file on it does nothing.

Hello, When I view some pages with inline video graphics, I see a garbled video frame. I have attached a screen grab from part of one screen. I have no issues with YouTube or other videos. It's just the graphics of some webpages such as looking at an Apple product on their site. I have not had this issue using Chrome under the same conditions. It's like I have a corrupted Codec or something. Does anyone have any suggestions? Thanks.

Hi,

I was using FF on Ubuntu 22.04.4 LTS. Had version FF 120.x and playing video in Netflix worked fine. Then I updated to FF 124.x and playing video stopped with error F7355-1203.

I've checked the DRM setting and it is enabled, I checked addons and I have OpenH264 and Widevine installed, both set to always active.

I've checked installed codecs and I do have libavcodec58 installed. No update for that available via apt. I also have ffmpeg installed, no problem with that either. I can play Netflix videos in Chrome, but not in Firefox now. Something happened to Firefox when I updated from 120.x to 124.x. Today I updated to 125.x, same problem, Netflix video won't play.

I've unchecked the DRM setting and re-checked it, and that does reinstalled Widevine but does not fix the problem.

Any ideas what could be the cause?

Contrast disappears when I klick 'Login' eg. on 'https://www.elektor.de/'; other browsers are ok. AdGuard on or off makes no difference. Kind Regards [removed email from public]

The latest update 141.0 (64-bit) has changed my default save location from g.drive to users//downloads. How do I change it back to g.drive? I use Firefox synced between 2 computers (1 desktop and 1 laptop). I use google drive so that I can access the same information on both devices. I NEED screenshots to be saved in a specific folder in g.drive. How do I do this. Before this update, there was not this issue. Thanks in advance.

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 prefer the tabs be below the bookmark bar, and successfully modified the CSS file to do this some time back. Now update 133 has once again pushed them up below the menu bar. What do I have to do to get them back where I want them this time? And why can't you just leave the tab location preference alone when doing updates?

I installed Firefox years ago. This morning, when I click on the browser icon, I get this message: Error platform '127.0.2' is not compatible with minVersion>= 127.0.1 maxVersion<= 127.0.1

What is going on? The browser updates itself so I don't do anything. But now, it doesn't work. I use an alternate browser to send this message to you.

I downloaded Firefox not too long ago to combat the fact the Microsoft Edge wasn't working correctly, but ever since I downloaded Firefox it's been making my computer run really slow on the browser. Things are often slow like scrolling up on and down pages websites like Pinterest, and the text when typing on Google docs takes a moment to show up after I've typed it and not instantly, for example.

I checked my computer's task manager because I recently cleaned the laptop, thinking that something else was causing it to be slow, but it isn't. I don't have many processes open on the computer mainly mandatory things and my browser, since I use my laptop mainly for school work, music, or writing. Firefox opens multiple processes, the highest being 21 at one time, and takes up most of the memory on the laptop. Is this normal? Because it takes 1,094.0 MB and keeps my laptop's memory at 90-91%. If it isn't normal, how can I reduce this as well as the lag on my laptop when Firefox is open?

I attached a photo as well.

Firefox releases email addresses and our data to third parties!

I installed the Arc browser and Arc offered to load my bookmarks from mozilla. Out of curiosity, I let it, and it loaded my bookmarks and folders smoothly. Arc didn't navigate Firefox to the login page, so Firefox released my information without asking me.

What probably happened in the background was that the Arc browser told Firefox which email address it was requesting data from, and Firefox handed over the data to it "on notice". Firefox was not even convinced that the real owner of the email address asked the Arc browser to synchronize the folders.

Is it the famous Firefox reliability?

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.

Hello. In the past two days I lose my tabs when I shut down Firefox. I used to be fine using the X at the top right and when I restarted the browser, all my tabs would still be there. Then they started going missing, so I started using the menu option to exit the browser. The tabs still went missing.

Then I noticed the square icon button on the extreme left and have discovered that Firefox has different windows, and that one of them (see attached image) has all my tabs in it, while the current window does not.

I cannot change Window 2 to be the current window. There is no obvious function on the page, nothing in settings and google is useless - I just get pages of discussion of how to tab between different apps on the desktop.

How do I make Window 2 the current window? See image.

Thank you

Every time I access the web I get a report from Norton saying "Threat secured". It attaches every single website that I open. See attachment for some exmaples (only variabole part of message shown apart from first one).This is occuring 50+ times a day but does not occur using Edge, so it appears to be related to Firefox. PLEASE help. Norton have not helped with this. Thank you- Colin O'Brien

Machine: Dell Inspiron 15 CPU: Intel i5-7200U @ 2.5 GHz OS: Ubuntu 24.04 LTS RAM: 16 GB GPU: AMD Radeon R5 M445

Yesterday I switched on my PC, opened Firefox and the home page was black. See the attached screenshot. This is not caused by some accidental switching on of the dark mode. Dark mode is clearly off. Neither can I adjust settings to make the Google home page revert to its customary light grey shade.

This isn't a big deal, I know. And it has happened before and in a short period gone away by itself. Maybe it is to do with a glitch in the latest Firefox version. But it has an unpleasant appearance and discourages surfing.

My Chrome Google home page doesn't have this issue.

Can anyone advise on how to fix this unwanted black screen problem ?

Roughly every 2 weeks I backup important files to a external hard drive.

One of the things I always backup is my Firefox profile. I have been doing this for years without any problems.

I 7zip my profile and copy it to the hard drive.

I tried to do this yesterday (July 25 2025), and was getting access denied messages for files in the profile. So I tried to simply copy the profile. Same thing access denied.

I cleared the history, used wise disk cleaner, rebooted my machine and tried again. Same thing access denied when trying to backup or copy the profile.

I am assuming that this is happening since 141 because I updated Firefox since the last time I backed up my profile, and never had a problem previously.

Could anyone have an idea what the problem is? Thank you for your time.

I have lost my tabs after the recent update. They used to show all tab groups in toolbar icon as mentioned here (https://support.mozilla.org/en-US/kb/tab-groups) in manage tabs section. Only the groups that were open are retained, the groups which were closed are lost. They contained important tabs which I haven't bookmarked. I didn't see any policy of removal of inactive tab groups after certain time, any help would be really appreciated. I use the desktop app on Linux.