you may need to reset site permissions:

Go to Settings > Privacy & Security > Permissions. Click Settings next to Location, Camera, Microphone, and find the denied site to allow access again.

Nothing changed. With other browsers I have access. Firefox refuses. How can I unistall Firefox but to delete also cached data and run it without automatically connect to my Firefox account?

Hello Bogdan,

I had the same issue! Here's how I solved it: In your Mac System Settings, go to Privacy & Security and find Local Network. There, you should see your applications that have access to your local devices. Please note that it may be in a different location or on tabs or so, depending on the Mac OS version that you use (I use Sequoia for example). You should see that Firefox has the switch disabled (grey). After switching on again, you'll probably need to restart Firefox or in any case close the tab or window and use a new one to re-access your local device. This worked for me, hopefully it also solves your issue.

@Firefox support: something basic like this should be in the Support site in my-maybe-not-so-humble-opinion...

i have the same problem, but neither of the suggestions works for me. Under Privacy & Security / Local Network, Firefox isn't even listed, and there's no way to add an application. Edge doesn't have access to the local network either, but the slider in the Local Network page is enabled. Safari doesn't have an application entry either, but it does have access to the local network.

The issue gets even worse as annoying and has only surfaced since Sequoia so is not a Firefox issue. On the upgrade to Firefox 131.0.3 from 131.0.2 just now I found that although access to the local network showed enabled as it had been, the Mac running Sequoia 15.0.1 did not recognise the Firefox upgrade as having this permission until it was rebooted. Accordingly I suspect the issue is pure Apple in Sequoia as never had this issue before, as Safari or Terminal can access the local network without issues and do not show as having permissions granted. I am expected now same issue to surface with Filezilla with its next upgrade as Filezilla also had to be granted permission on its first run which I had not used since I moved to Sequoia. I also discovered the new security configuration closes access to router configuration screens via Firefox which could be very difficult if the user does not understand and likes other browsers than Safari.

Hi everyone

The issue gets even worse as annoying and has only surfaced since Sequoia so is not a Firefox issue. On the upgrade to Firefox 131.0.3 from 131.0.2 just now I found that although access to the local network showed enabled as it had been, the Mac running Sequoia 15.0.1 did not recognise the Firefox upgrade as having this permission until it was rebooted. Accordingly I suspect the issue is pure Apple in Sequoia as never had this issue before, as Safari or Terminal can access the local network without issues and do not show as having permissions granted. I am expected now same issue to surface with Filezilla with its next upgrade as Filezilla also had to be granted permission on its first run which I had not used since I moved to Sequoia. I also discovered the new security configuration closes access to router configuration screens via Firefox which could be very difficult if the user does not understand and likes other browsers than Safari.

Indeed, MacOS is to be blamed. Somehow now it is working on Sequoia 15.0.1. But in the meantime there was no update and no restart. Just after 2 days it started to work. Thank you everyone for helping me

Unhappily the Sequoria bug can resurface on a Mac reboot too with the same version of Firefox reopening that worked fine before. The issue seems to be that the setting is not sticky but it can be toggled back on in this situation.

Just updated from Sonoma to Sequoia 15.2 and running Firefox 134.0.2 - same problem except not only can't I access my modem/router webpage, neither can I access the webpages for my x2 NAS !!!

Fortunately, I also run Safari and DuckDuckGo browsers and can access the webpages that way.

I have found that if I open any of these webpages and then open Firefox, I can sometimes access the webpages from Firefox but the next time I open Firefox, the problem returns.

Tried all the suggestions above - none work reliably, most just don't work.

While it seems Sequoia has caused the problem with Firefox, as it isn't causing the same problem with Safari or DuckDuckGo browsers, I'm not sure it is entirely the fault of Apple …

Maybe found a solution which at least seems to work for me.

Quit Firefox 134.0.2, open macOS System Settings -> Privacy & Security -> Local Network and turn OFF allowing Firefox to access the local network.

Quit System Settings and all other apps, shutdown the Mac and restart.

Now open macOS System Settings -> Privacy & Security -> Local Network and turn ON allowing Firefox to access the local network. The open Firefox and I could access the web pages for my modem/router and x2 NAS.

Let's see if it remains OK.

Yes, toggling System Settings -> Privacy & Security -> Local Network -> Firefox off and back on enables access to the LAN but as mentioned above, it doesn't "stick".