Firefox Community Forum

Hi Community,

I’ve used Firefox for over 20 years and it’s always been my main browser, but since updating my Mac to macOS 27, Firefox has become unusable with one of my essential web apps (FlightLogger). The first page after logging in loads normally, but any click or navigation after that fails. The header stays visible, the rest of the page stays blank, and clicking links only adds a “#” to the URL with no content loading.

Safari works perfectly on the same machine and same network.

In Firefox’s console, every JavaScript file coming from CloudFront fails with “CORS request did not succeed (Status code: null)”, and I also see repeated “A ServiceWorker intercepted the request and encountered an unexpected error” messages. Module scripts are also blocked with “Module source URI is not allowed in this document.”

To rule out local issues, I’ve already reinstalled Firefox, created new profiles, cleared all caches/cookies/service workers, disabled all extensions, disabled DNS‑over‑HTTPS, disabled Enhanced Tracking Protection, reset macOS network settings, checked proxy settings, and tried different networks. The problem persists even with a completely fresh Firefox install and profile.

This started immediately after upgrading to macOS 27, and only affects Firefox. Safari loads the same CloudFront assets without any issue. It looks like Firefox can load the initial HTML but cannot fetch any CloudFront‑hosted JavaScript modules, which breaks navigation entirely.

Has anyone else seen this after updating to macOS 27, or found a workaround? I’d really like to keep using Firefox as my main browser.

Thanks in advance

How to force Firefox to display current search results. The internet has become like local FM radio. You can never find or hear what you want. When I search for latest news I don't want to read about Jimmy Carter or Barack Obama. Is there a setting to only show the latest results?

Hello,

I would like to report an issue with the Firefox Add-ons Store.

Recently, I suddenly encountered an "HTTP 406 Not Acceptable" error when trying to access the Firefox Add-ons Store. The store is completely unusable for me right now.

Here are the specific details:

Issue description: I have tried accessing the store on every network available to me, including mobile data, my office wired network, and my home wired network. Unfortunately, I get the same 406 error on all of them.

Timeline and context: Everything was working perfectly fine last week. I was able to search for and install a Markdown add-on without any issues. However, starting this week, it suddenly started returning the 406 error.

Additional troubleshooting:

I am not using a VPN or proxy. However, if I enable a proxy, the Add-ons Store works normally.

There is no antivirus software or firewall blocking Firefox's network requests.

Other websites load normally. Even mozilla.org works fine, but addons.mozilla.org does not.

I have also tried changing to other DNS resolvers, but that did not help.

Could you please help me understand why this is happening and how I can resolve it?

Thank you!

I was attempting a search for a local winery, incognito, when an account for a completely unrelated search popped up and Avast security messaged this account is compromised head back to safety. It was for a clothing company with no similar company name to the local winery I was searching for.

Hello, this is the basic problem:

The short version is that there is a problem with Firefox not interacting with the scrub bar and volume bar. (all other controls work fine) We know it's a Firefox thing because everything works with Brave. (or an interaction between Firefox and the OS at least, Firefox is heavily involved)

There is more detail and we have done some work on it here: CashyOS forum post

You can use the Firefox manifesto V0.2. video for an example, as it displays all the above problems for me.

I can get you guys whatever other data might be needed, but I kinda need an idea where to look to try and fix this, as all the other posts I have managed to find don't seem to have similar enough issues to work.

Mozilla Firefox keeps crashing repeatedly while I am searching or typing, and the problem persists. Why is this happening, and what is the solution? I request you to investigate and fix this crashing issue as soon as possible.

Firefox is showing me an older version of a website. When I'm opening the same site in other browser it is changes, but mozilla is still showing me previous version. what should I do to fix it?

Hello,

I would like to obtain the complete release history of Firefox ESR Portable, including:

The exact release date of each Firefox ESR Portable version. The corresponding Firefox ESR version number (e.g., 115.x ESR, 128.x ESR, 140.x ESR, etc.). Any available information regarding delays between the release of Firefox ESR by Mozilla and the release of Firefox ESR Portable.

Could you please provide a list of all Firefox ESR Portable releases along with their release dates, or direct me to an official source where this information can be found?

Thank you for your assistance.

Using the latest Firefox update with Windows 10. I've got three popups in the lower right corner of my screen (see uploaded image), and each refreshes periodically with a musical phrase that sounds like a smartphone notification. Though each says "Mozilla Firefox" in the upper left hand corner, the popups are present whether the browser is open or not. All three say, "via da75iiinaffc73ar8f20.yird-protect.pro".

I've already gone to Settings, cleared my History, made the recommended changes in Permissions and Data, and closed and reopened the browser. The popups remain.

I just recently installed the VPN on Firefox. It hadn't shown up because of my privacy settings. It works fine except for the United States connection. When I choose the other countries, it works fine, but when I choose United States, it still shows Japan (where I live). It still shows Japan, but it does have an effect. It changes it to Tokyo, where I don't live. So, the vpn is having some effect, but it is just not connecting to the United States. Why is that?

Download FF install sign-in > said success then show warning

``` Are you sure you want to sign in to sync?

A different user was previously signed in to sync on this computer. Signing in will merge this browser’s bookmarks, passwords and other settings with xxxx@gmail.com ````

Press continue, the pop-up still appear and the sign-in was false positive.

FF version : 156.0 (64-bit)