Firefox Community Forum

Hi, I'm not sure if this is a bug, or me not using FF properly.

I want Firefox in general to ask me, which profile to use when started. So in the Profile-Manager, I removed the checkbox for "Use selected profile without asking as startup".

Now, I wanted to create a shortcut for a specific profile, so I tried running `firefox -P "myProfile"` or even `firefox -p "/path/to/myProfile"`. In both cases I get the window asking me which profile to use.

Debian 12.6 - SwayWM Firefox 128.0 (64-bit)

I am using Linux Mint with Firefox 127.0.2 (64-Bit)

In Preferences Applications, setting

 CSV-Dokument      to    open with firefox

opens edless new firefox Tabs - so I had to kill firefox. (setting CSV-Dokument to open with OpenOffice works fine. But this is not what I want.)

In Preferences Applications, I found further CSV types: application/csv-Typ CSV Document (application/text) CSV Document (octet/stream) CSV Document (application/x-download) Which applications should I use for them ?

I found the file "mimeTypes.rdf". However, I am not familiar with the syntax.

Any advice returned by Google seems to be obsolete or only worked perhaps in older versions of Firefox. The main idea of using userChrome.css to override the default styles for Reader View does not seem to work. My userChrome.css file does work on other items though (like removing the sidebar width restriction).

Whatever advice I find via Google perhaps cites outdated CSS selectors, but current selectors do not seem to be documented anywhere by Mozilla. Moreover, I cannot find any file on my local drive named aboutReader.css when using find or grep commands in bash, those this file name is alluded to when viewing a page in Reader View and then in turn viewing source on that transformed page.

Moreover, addons that would allow me to change the colors seem to be restricted in Reader View.

It does seem like something has changed in recent Firefox updates but I can't remember when I last saw, for instance, links in dark mode Reader View that were still pink (whereas now they are blue, and impossibly dark to see, especially when you are disabling as much blue light as possible through your operating system). I need a higher contrast color for links in dark mode Reader View so I can actually see them.

I can alternatively use the Tranquility Reader addon and have custom colors, but A) that addon does not work with the Automatic Reader View addon, whereby I can always have various sites appear in some sort of "reader view" whether the native one or Tranquility Reader, and B) hitting refresh when in Reader View will defeat some soft paywalls but this does not work with, e.g., Tranquility Reader, so I still would prefer to be able to custom colors in the native Reader View feature, rather than rely on an addon.

1. Where are the current styles for Reader View even documented? 2. Is overriding them now restricted? 3. Why did the link color change from pink to blue in newer versions of Firefox (this is a terrible accessibility bug)? 4 .Where is the alluded to aboutReader.css stylesheet actually stored on my computer (it doesn't seem to be a file on the filesystem in the Firefox profiles folder, it seems more like it is embedded in the Firefox binary/executable)? 5. Will Firefox settings ever allow us to set colors specifically for Reader View (I don't mean the override settings for all web pages, particularly web pages not being rendered in Reader View ... that setting does not help in Reader View, nor would it be the desired preference for pages not in Reader View)?

Thank you.

This issue is happening with every newly installed add-on, but not with add-ons installed on or before Aug 3, 2024. The add-ons are installed via addons.mozilla.org. To rule out the possibility that it's happening only with specific add-ons, I also installed one of the random recommendations on that page, Augmented Steam which has 54,248 users, and it happens with that one as well.

I'll click Enable, but the prompt appears every time I restart Firefox.

What I've tried (with a restart after each attempt):

• Clear the startup cache
• Delete extensions.json
• Delete compatibility.ini
• Via about:config deleted extensions.databaseSchema and extensions.getAddons.databaseSchema
• Excluded Add-ons from syncing

I've noticed the following in extensions.json for each of the recent add-ons after restart:

• syncGUID changes to presumably random new value
• active changes from true to false
• userDisabled changes from false to true
• seen changes from true to false

Hello, in past versions of Firefox, I was able to follow the steps on this page to set a custom HTML file on my PC as my home page for new tabs: https://peterries.net/blog/firefox-ubuntu-local-file/

I have Firefox 107.0.1 now and it's not happening. When I open the browser from scratch, I see my custom home page file. But when I open a new tab, I just see a blank screen. If I then click the Home icon on the toolbar, I do see my custom HTML page, but I don't want to have to click that button for each new tab.

Right now, in my settings, I have the URL to the page set as the custom URL for the HTML fiile, like this:

file:///home/peter/Documents/homepage/peter-home-homepage.html

That works. And I also have followed the steps on that blog post to customize my /usr/lib/firefox/autoconfig.cfg and my ../firefox/defalults/pref/autoconfig.js files. That's no longer working.

Did something in a recent version change? Is this no longer supported? Thanks for any ideas!

My system broke during an update. Now I want to import my old Firefox userdata, but everytime I try to use the old data firefox just forces the creation of a new profile?

Is it completely impossible to recover data not created with the same firefox version?

Every time I open Firefox after closing it, I get the message below. I can click the button to restore session and it works every time. With each update, I hope to never see this message again, but after installing a new version on Ubuntu today, I see the same familiar message. This is not linked to a computer, or an operating system because I've seen this on both Ubuntu and Mac. If Firefox could literally just click the button that would be awesome.

Sorry. We’re having trouble getting your pages back.

We are having trouble restoring your last browsing session. Select Restore Session to try again.

I am using Firefox v140.0.1 Snap on Kubuntu 25.04, Kernel 6.14. Since the Firefox update in the past couple days, the mouse cursor has started appearing huge and slightly blurry (as though the image is scaled up) in Firefox and nowhere else. The size is visually annoying, and occasionally difficult to know exactly where I'm clicking (trying to move the caret in a text box for example). It also appears to be a different style from the main desktop cursor, the shape and color are ever so slightly different, but this may already have been the case and I simply didn't notice because of the previously small size. Firefox doesn't have its own built in cursor settings that I can find, nor obey the system cursor settings. I have a high DPI display so perhaps it is being over-compensated for? e.g. both the system and Firefox are scaling the cursor up, assuming the other hasn't done it already, resulting in a cursor that's too big.

I am on endeavourOS (linux). Whenever I try to upload images for a profile picture to sites like youtube or X, the image becomes corrupted and doesn't upload correctly. It did this with whatsapp too and I had to use a separate app for it. Other posts said that disabling "privacy.resistFingerprinting" would fix it, but it's already disabled.

Attached below are an example of this bug and the contents of this image when viewed on a text editor.

Good morning, today I downloaded Debian 13 Mate version and to install Firefox I entered the following commands taken from https://support.mozilla.org/it/kb/installare-firefox-linux#w_installare-firefox-tramite-il-pacchetto-deb-per-le-distribuzioni-basate-su-debian-consigliato and the commands were

sudo install -d -m 0755 /etc/apt/keyrings

wget -q https://packages.mozilla.org/apt/repo-signing-key.gpg -O- | sudo tee /etc/apt/keyrings/packages.mozilla.org.asc > /dev/null

echo "deb [signed-by=/etc/apt/keyrings/packages.mozilla.org.asc] https://packages.mozilla.org/apt mozilla main" | sudo tee -a /etc/apt/sources.list.d/mozilla.list > /dev/null

echo ' Package: * Pin: origin packages.mozilla.org Pin-Priority: 1000 ' | sudo tee /etc/apt/preferences.d/mozilla

sudo apt-get update && sudo apt-get install firefox firefox-l10n-it

but I get this result OpenPGP signature verification failed: https://packages.mozilla.org/apt mozilla InRelease: Sub-process /usr/bin/sqv returned an error code (1), error message is: Signature by 35BAA0B33E9EB396F59CA838C0BA5CE6DC6315A3 was created after the --not-after date.Il repository "https://packages.mozilla.org/apt mozilla InRelease" non è firmato.

What mistake could I have made? Apart from the fact that now we use sudo apt update && sudo apt install Thank you in advance for your response.

I am using Firefox 127 on Ubuntu.

When I press the Control key, I often lose focus in the window I am currently viewing. This is annoying as it prevents me from copy-pasting for example.

Sometimes the focus is back when I release Control, sometimes it is lost and I have to click again on the text field. It does not happen on all websites, for example support.mozilla.org works well, but it happens on duckduckgo or overleaf.

It does not seem to be the same as existing issues such as [the "show mouse when press Ctrl" of Ubuntu] (it is disabled) or an addon (the problem still happens in safe mode).

In case it is useful, when I press Control the tab bar background goes slightly darker, see attached images.

Thanks for your help :) Nicolas

Hi, my Machine updated from 140.0.4 to 141.0 since then I cannot start up Firefox anymore. On startup after a short pause the Crash Reporter shows up - interestingly the Crash Reporter may enter a endless loop and opens up multiple times. While that the CPU load is at 100%. I tried

• `firefox --safe-mode`
• `firefox --ProfileManager`

as well, for those I get the same behavior. I tried downgrading to 140.0.4 - after that a profile dialog shows up which tells me that a new profile needs to be created due to a downgrade. After that Firefox comes up fine with the new vanilla profile. IF Firefox updates to 141.0 (in background) the next startup with the vanilla profile doesn't work gain. Which brings me back to the initial problem.

Workaround for now:

• download 140.0.4
• create a fresh profile
• immediately disable auto update
• live with the empty profile

My environment:

• Linux Debian 12 on x86_64
• KDE Plasma
• nvidia drivers installed
• I am using Firefox from `https://download-installer.cdn.mozilla.net/pub/firefox/releases`

Did Not Connect: Potential Security Issue

Firefox detected a potential security threat and did not continue to nrega.nic.in because this website requires a secure connection.

What can you do about it?

nrega.nic.in has a security policy called HTTP Strict Transport Security (HSTS), which means that Firefox can only connect to it securely. You can’t add an exception to visit this site.

Probably nothing, since it’s likely there’s a problem with the site itself.

For the last 2 weeks I started having problems with Firefox working consistently. Sometimes only tabs crash, sometimes Firefox crashes. It is not tied to any actions, a tab can crash even if you don't perform any actions in the browser. I have tried clean install on Fedora and Vanilla OS, native and Flatpak packages. The result is always the same - tabs or Firefox crashes every few minutes.

I have downoloaed Firefox offline installer (a .xz file) from here:

https://download-installer.cdn.mozilla.net/pub/firefox/releases/139.0b9/linux-x86_64/en-GB/

I have also downloaded a .asc file, presumably a pgp signature.

Now both files are saved locally in my computer.

Assuming Linux latest release, how do I verify the contents of the offline installer file (.xz) from the Linux Terminal? I have install gpg tools. And commands like ```gpg``` are available.

What I did so far:

 gpg --show-keys --with-fingerprint firefox-139.0b9.tar.xz.asc

with this output:

 gpg: no valid OpenPGP data found.

Do you really want us to verify the contents of the installers you provide? A sha256 sum would be great, though not as secure, for when the GPG predictably fails for the ordinary user due to its huge and useless complexity and bureaucracy.

Dark mode in Firefox has broken just now. The issue appears restricted to Firefox - all other elements in environment (Ubuntu/Cinnamon) appear to be operating correctly.

The elements at the top of the screen and some menu screens are now white rather than dark grey. Due to a neurological condition this causes near-instantaneous cluster migraines.

Is there a way I can fix this? Is there a way you can fix this? Is there a way to access the web without a browser? (eg through the text terminal)

I am experiencing an issue where Google.com (other google domains work fine) will not load in Firefox, resulting in an infinite loading loop. Other browsers on the same system (Brave) work fine.

Here are the steps I have already tried:

Reinstalled Firefox completely

Removed Firefox via sudo apt remove --purge firefox -y

Cleared all user profiles and caches: ~/.mozilla/firefox, ~/.cache/mozilla, ~/.config/Mozilla

Reinstalled via Flatpak

Tested network connectivity outside Firefox

curl google.com works correctly

DNS resolution works via getent hosts google.com in the host system

Checked proxy settings

Ensured “No proxy” is selected in Firefox → did not resolve the issue

Tested in Safe Mode (disabling extensions)

Problem persists, so not caused by extensions

Tried disabling IPv6 inside Firefox

network.dns.disableIPv6 set to true → no effect

Cleared DNS cache inside Firefox

about:networking#dns → clicked “Clear DNS Cache” → no effect

Disabled DNS-over-HTTPS (Secure DNS)

about:preferences#privacy → “Use secure DNS” → disabled → no effect

Disabled HTTP/3 (QUIC)

network.http.http3.enabled set to false → no effect

Verified Flatpak network permissions

flatpak info --show-permissions org.mozilla.firefox shows network access allowed

Inside the Flatpak shell:

flatpak run --command=sh org.mozilla.firefox getent hosts google.com

→ returns only IPv6 address: 2800:3f0:4001:839::200e google.com

Firefox version 145.0 in Linux Ubuntu 22.04.5 LTS. When I open Firefox all tabs from previous session are gone. On "Startup" I have checked "Open previous windows and tabs". Which worked before but not now. It is very frustrating. How do I fix? The Profile Manager opens the settings and "Open previous windows and tabs" is checked. Checking "ask before closing multiple tabs" doesn't help.