Firefox for Enterprise Community Forum

GNU nano 8.6 /etc/firefox/policies.json {

 "policies": {
   "DisableFirefoxStudies": true,
   "DisableTelemetry": true,
   "DisableSystemAddonUpdate": true

   "Preferences": {
     "app.normandy.enabled": false,
     "app.shield.optoutstudies.enabled": false,
     "extensions.autoDisableScopes": 15
    }
  }
} Hidden modifications to settings and extensions is absolutely not OK!!!!!!

This is a security environment.

I previously posted this question: https://support.mozilla.org/en-US/questions/1495577

Asking how to use the "intl.accept_languages" setting within the JSON for the new preferences setting within group policy.

A moderator posted this as a comment which I have only just noticed: "The value is a string, so it has to be in quotes "en-GB"" - the post is now too old for me to reply.

I'm still having issues using this setting even after putting the name in quotes. I've tried:

"intl.accept_languages": { "Value": "en-GB", "Status": "user" }

"intl.accept.languages": { "Value": "en-GB", "Status": "user" }

But neither work, please can someone clarify what exactly needs to be used within the JSON?

Greetings!

I am using the firefox enterprise version and I have noticed an issue that the browser does not capture mouse events when the pointer is at rightmost edge of the firefox window. For example, on this website near the edge the pointer would initially focus on the scroll bar and then lose focus at the edge (see attached images).

This issue does not persist on x11, and only seems to exist on wayland. It also exists on other flavours of firefox on wayland.

If more information is required, feel free to send me a ping.

I know nothing about the dev options for Internet settings and minor turned on and it says the remote server is set to production. No flipping idea what this is. Can somebody please help me?

I am logged on to my Credit Union and attempt to download my statements. When using Firefox I get the message: {"Errors":["Authorization has been denied for this request."]}

When I contacted my CU, they said to add an URL to the Manage Exceptions. This worked, but I want to know why Firefox needs this but Chrome doesn't.

Hello,

I had issue to verify the cert on android app for https://partners-enrichment.heytelecom.be. On Windows I didn't have the same issue.

version 144.0.2 / build id 20251027123126 / target arm64-v8a armeabi-v7a x86_64 Device: Samsung S22 / One UI 7.0 / Android version 15 / version S901U1UES8FYI2 / Security patch level September 1, 2025

Error: Secure Connection Failed, because its certificate issuer is unknown, the certificate is self-signed, or the server is not sending the correct intermediate certificates.

CertChain RCA: DigiCert Global Root G2 DCA: DigiCert Global G2 TLS RSA SHA256 2020 CA1 cert: partners-enrichment.heytelecom.be

1) I couldn't check the cert from the gui as on windows. Shield in search bar / Connection not secure doesn't opened the cert. Is it expected?

2) I found this helppage: https://support.mozilla.org/en-US/kb/setting-certificate-authorities-firefox

Unfortunately about:preferences isn't available on android (ref. https://www.reddit.com/r/firefox/comments/u593x0/how_to_access_to_aboutpreferences_on_android/)

I see in about:certificate which is the correct RCA (I verified the pem file with the root). DigiCert Global Root G2

Where do I check the Intermediate CA's (DCA)?

3) When exporting the RCA it has been download as: digicert-global-root-g2.pem.txt Why the txt at the end?

On Windows it downloads as digicert-global-root-g2.pem

Kind regards,

I have several users that are running Firefox 137. When attempting to update, they get the message that the organization has blocked updates. There is nothing I can see that we have done. Attempted to update registry and .json file. I cannot find where the block is coming from. Do I need to delete and reinstall?

We are currently rolling out a profile management solution based on Ivanti User Environment Manager. In order to configure file includes and excludes in the profile management tool, we have to “standardize” the Firefox profile path in the filesystem. We have implemented a PowerShell script, which reads the currently used profile from %appdata%\Mozilla\Firefox\install.ini, renames the appropriate profile subfolder to “firefox.default-esr” and replaces the entries in installs.ini and profiles.ini.

The script seems to be reliable. However, for around 10% of the users, we are seeing issues when the user launches Firefox after the “firefox profile migration” happened. Firefox opens but none of the GUI controls is accessible. Firefox is completely unusable. See screenshot attached.

We do have workarounds to resolve this issue, such as completely wiping the %appdata%\Mozilla\Firefox folder and let Firefox re-build everything from scratch. But we are still trying to find the root cause the issue, because our customers have more than 100k clients, what will be a big impact and hard to handle for the helpdesk.

We are currently unable to reproduce the issue on test clients. Even copied Firefox profile folders form affected clients don’t show the issue on other clients.

Therefore we want to find out and ask for your help:

- Is there a supported way to “standardize” the filesystem folder name of the Mozilla Firefox (ESR) profile of a user? - What are the files within a Firefox profile that are required for the profile and the application itself to properly start? - Do you have any idea which files in a Firefox profile (in a corrupted state) could cause our issue?

I want nothing to do with AI.

I have unticked perplexity.ai in preferences#search but every search from the search bar and address bar goes to perplexity.ai then immediately crashes and displays "Internal Error".

To use DDG I have to type duckduckgo.com on the address bar then search from there.

Firefox 140.4.0 ESR.

I've' scanned the PC with malwarebytes. I restored windows from a backup image I haven't made any changes to the PC at all. Was working fine in the AM but by later afternoon, it started using perplexity.ai exclusively.

How do I get rid of perplexity.ai

Hello everyone,

i would like to ask if anyone have/had similar experience as me.

Im managing browsers in my company (Chrome, Edge , Firefox) via on-prem/Cloud solutions, approximately 300k users.

We are observing that most of the users are no longer using Firefox that often , leaving Firefox unpatched and therefore risking potential malware/ other attacks.

Of course that brings attention from our security team and now , we have to deal with it :)

Option to remotely uninstall (Intune , SCCM) is option number one of course, yet not the desired one.

We would like to check if there is an option how to "silently" update all the browsers with version N-1. We have looked into scripting, resulting into UAC prompt all the time, which is , of course, not desired.

Does anyone had similar experience, where you had to deal with similar use case ?

Please let me know

Have a great one you all !! Tomas

I look after about 20 PCs. All Windows 10. All were running Firefox ESR ranging from 115 - 128. As I get time I update each to the latest 128.x. Using group policies I've disabled all update settings.

However, on two of the PCs, they have updated to v139.0.1. Both of the users swear they did not manually do any update. I can't figure out how they got downgraded to the retail channel.

So my question is, since 128 < 139 how can I get them back on to the ESR channel, without loosing history, bookmarks, passwords and saved logins? I gather FF's installer will detect 128 as an older version and throw an error?

ESR -> Retail to me is a downgrade. So is it possible then to upgrade back to 128.11.x?

Each PC is refreshed annually and the only backup of the profile folder I have is from the last refresh, which in most cases in 8-9 months old.

Is there any way to find out why the downgrade happened when group policy forbids it, and the user did not manually download and install the latest version?

When these downgrades happen they break things. For example, when one PC was downgraded to retail his outlook.com email no longer works. If he uses his laptop which is on 128.11.0 it works fine.

Hello Everyone,

I am seeking assistance to configure Firefox browser so that internet access is blocked when the browser cannot download or access the proxy Auto-configuration (PAC) file. Our organisation enforces all web traffic through proxy servers defined by a PAC file. For compliance and security reasons, users should not have any direct internet access unless the browser is able to successfully retrieve and apply the PAC file.

The desired behaviour is:

1. Firefox attempts to download the PAC file from a defined URL. 2. If the PAC file is unreachable or fails to load (e.g., due to network restrictions or the device being outside the corporate network), Firefox should "fail closed" - meaning it should not allow any direct internet traffic. 3. This is effectively a "fail-block" mode: no fallback to direct connections, and no cached or bypassed proxy settings should allow internet browsing.

This behaviour is critical to prevent devices from accessing the internet without applying corporate proxy rules. I would like to know:

1/ Whether Firefox currently supports a setting or policy that enforces this fail-block condition when the PAC file is unavailable. 2/ If not, whether there are recommended configurations or enterprise policies (e.g., via `policies.json` or Group Policy templates) that could achieve equivalent enforcement.

Thank you for your assistance and guidance.

Hi,

I have 2 machines (Win10 and Win11) with FF 140.3.1esr (32-bit) installed which demonstrates the same failure when I enter one site's url:

PR_CONNECT_RESET_ERROR

Chrome at the same machines goes at this url w/o any failures. Any ideas what to change on "about:config" in FF to allow it opening this url w/o such error?