It works for me. see screenshot Post a full browser screenshot showing the issue and block any personal info. What happens when you go to https://www.xfinity.com/ Who are you using for DNS?

Did you try to reboot the computer or use "Forget About This Site"?

"You don't have permission to access..." errors are characteristic of a firewall that protects the server against misuse and this firewall thinks something is suspicious about the HTTP request. If you use a proxy or VPN, try to use a direct connection. Select "No Proxy" if "Use the system proxy settings" or one of the others do not work properly.

• Settings -> General -> Network -> Connection -> Settings

You can try to clear the Cache and remove the Cookies for websites that cause problems via the padlock button or via "3-bar" Firefox menu button (Settings) to see if that fixes it.

• https://support.mozilla.org/en-US/kb/firefox-cant-load-websites-other-browsers-can

I've seen cases where having enabled Resist Fingerprinting was causing this issue.

• https://support.mozilla.org/en-US/kb/firefox-protection-against-fingerprinting

Start Firefox in Troubleshoot Mode to check if an extension is causing the problem.

• https://support.mozilla.org/en-US/kb/diagnose-firefox-issues-using-troubleshoot-mode

If this all doesn't work, try "Forget About This Site" in the right-click context menu of an history item. Note that this might remove saved passwords for this website, so make a note if you have any.

• https://support.mozilla.org/en-US/kb/delete-browsing-search-download-history-firefox

Here are the answers to the suggestions above by jonzn4SUSE and cor-el.

Regarding DNS I use 1.1.1.1 (Cloudflare) as the primary and 8.8.8.8 (Google) as backup. I tried changing those to my ISP (Xfinity) and it made no difference. I tried using my smart phone as a hot spot which then uses a different DNS. Again no difference. So it does not seem be related to my ISP or DNS. Also it works fine using Chrome or Edge and they use the same ISPs and DNS.

I have tried "forget this site", I have tried all the proxy settings (I normally don't use a proxy), I have turned off the firewall (both on PC as well as in the router) but remember it works with Chrome and Edge. I tried turning off all the Firefox protections (fingerprinting, cookie blocking, etc.). I have cleared cookies, cache, etc. I tried creating a new profile. I tried doing it in a private window I tried troubleshoot mode (i.e., all add-ons disabled).

I have tried everything I could think of and everything I found with Google searches of people having this problem. Some have had it on other sites using other browsers. But for me it only happens with Firefox on Xfinity. And it only started happening today.

It didn't work 5 minutes ago. So just now as I went to get a screenshot as requested by jonzn4SUSE it started working! Very strange. It hasn't worked all day and I have tried many times including all the things I mentioned above.

Maybe it is something specific to the Xfinity website although why it would only fail on Firefox I don't know. Maybe it is related to the user agent string. I have had other sites that complain that I am not using one of their supported browsers but they usually work anyway. And Xfinity doesn't tell me that.

Firefox is my preferred and default browser (has been since about 2005). I have about 10 sites that I use that don't play well with Firefox and I use Chrome for those. But the Xfinity problem was new today.

Thanks for all your suggestions. If it starts happening again I will let you know.

Charley

Well, it stopped working again. It's only been about 20 minutes since it was working.

I try to login. I put in my username and click on the "Let's Go" Normally at that point I get a screen asking for a password. Instead I get:

Access Denied You don't have permission to access "http://login.xfinity.com/login" on this server.

Reference #18.4c94d817.1724554138.16474a63

https://errors.edgesuite.net/18.4c94d817.1724554138.16474a63

Reboot the computer into Windows Safe Mode with network support to see if that has effect.

• https://www.bleepingcomputer.com/tuto.../how-to-start-windows-in-safe-mode/
• https://www.digitalcitizen.life/4-ways-boot-safe-mode-windows-10/

It worked in safe mode with networking! Then I rebooted again and it stopped working. Very strange.

So I tried killing off each background process (one by one) to see if I could find one that made a difference. No matter what I killed (including turning off my antivirus and firewall), it still doesn't work.

And it seems to be specific to Firefox as works with Chrome and Edge.

Note that with turning off third-party firewall/AV you usually only disable its user interface, the underlying services may still be active.

What security software do you have?

Tried it again in safe mode. Fails in safe mode! So it is probably not my security software (Norton) or background programs. As I said, sometimes tonight it worked in normal mode and stopped again. So the first time I tried in safe mode was probably just coincidental.

I tried downgrading to the previous Firefox (129.0.1) - no difference. Reinstalled current version (129.0.2) - no difference.

What security software do you have?

Drum roll please...

Today it was magically working again for a little while. Then it stopped again.

And today it worked for a little while. Then it stopped again. Always works on Chrome and Edge. Could be a problem with the Xfinity website. Otherwise I don't understand why it works sometimes and doesn't work sometimes.

Can you disable norton, reboot, and try again. Doubt it's a site issue, I can get in without any issues. see screenshot Are you running Windows home or pro?

Disabling Norton is difficult without uninstalling it. I did turn off everything I could. Still fails. Tried again in safe mode, and I verified that in safe mode Norton is not running. Still fails.

Several times today it worked once or twice then stopped working. Then later worked again once or twice. I wonder if it is something related specifically to the Xfinity website.

Sometimes deleting all cookies got it working once. Then it failed. Other times deleting all cookies made no difference.

Very strange. Always works with Chrome or Edge.

While I would like to figure this one out, I will probably just use Chrome when I go to Xfinity.

I have few other sites that only work well on Chrome. Some don't work at all on Firefox. Some work better with Chrome. But I prefer Firefox.

It would be helpful if you post a full browser screenshot like mine so we can see what going on. If you can't see any benefit in providing it, then this "issue" is a wrap for me. Jones out.

jonzn4SUSE attached are two screenshots. The first shows the screen after I go to https://login.xfinity.com/login

The second screenshot shows what happens after I put in my username and select "Let's Go"

As I said, I look like to fix this. It is intermittent but mostly fails. It used to always work. But then for about the last week is has been failing most of the time.

If we can't figure out what is going on (which I am hoping will help the Mozilla team improve Firefox) I can just use Chrome when I need to go to Xfinity, which I do every day to check on both my and my wife's emails for spams and other junk before we download them into our mail apps (Microsoft Outlook).

Charley

Thanks for the screenshots Charley & all the testing you've done in Windows Safe Mode. Really appreciate it!

I think this might be caused by one of your Firefox addons. The addon Ghostery. It used to be good back in the day but I've been researching it & it breaks random websites. Other adblocking or privacy addons you have might also be causing the "You don't have permission to access this error *link* on this server".

Ghostery broke a popular bank's login page so the user couldn't sign in at all, no one could find out why until they disabled it: https://support.mozilla.org/en-US/questions/1368050#answer-1484115

To disable Ghostery and other addons: Disable or remove Add-ons

If disabling Ghostery doesn't work, please try turning off all your Firefox addons and then try going back to Xfinity's page a bunch of times to make sure it keeps loading correctly.

Then you can try turning on your addons again one by one. Making sure to visit Xfinity a couple of times before going back to turn on another addon.

You have a lot of addons so if you can write them down or copy their names here I would appreciate it. Go to about:support in your address bar, you will find a nice list of your addons you can highlight & copy. Scroll down to the Add-ons section to see them.

Example list of addons you will see: Add-ons Search Detection extension 2.0.0 true addons-search-detection@mozilla.com Google search link fix extension 1.6.10 true jid0-XWJxt5VvCXkKzQK99PhZqAn7Xbg@jetpack System theme — auto theme 1.3 true default-theme@mozilla.org Dark theme 1.2 false firefox-compact-dark@mozilla.org Firefox Alpenglow theme 1.4 false firefox-alpenglow@mozilla.org Light theme 1.2 false firefox-compact-light@mozilla.org

I have tried disabling all the addons. I have tried troubleshoot mode (which I think also disables all addons). Doesn't make a difference with Xfinity. Some days it works for a little bit then stops. That happened yesterday. Today it didn't work at all.

After doing the about:support as you suggested, I see addons which I didn't put on. I don't know how or why there are there. Some examples: amazon.com extension, ETP search volume study (seems to be from Mozilla), bing extension (seems to be from Mozilla). I think the amazon and bing are so I have the option to pick those as a default search.

Yes I know about Ghostery. I find it useful. I have to mark some sites as trusted and that usually fixes problems. Some sites I need to turn off AdBlock. But none of those seem to be related to my Xfinity issues.

By the way I have Ghostery in Chrome also and some sites that don't work on Firefox do work on Chrome even with Ghostery.

Alright Charley, thanks for taking a look. I really thought I was on to something there. This Access Denied error is just one of those hardest ones to solve it appears. I'll let you know if I find anything more definite. I support your strategy of visiting problematic websites like this in Edge or Chrome where it works without any errors. Unfortunately some websites force you to do that.

The things you found in about:support:

• Amazon & Bing search extension - you are correct, those are just options for your default search. They are from Mozilla and safe. Those extensions have "@search.mozilla.org" at the end of their name.
• ETP search volume study (seems to be from Mozilla) - Yes, that's from Mozilla. A study of the built-in Enhanced Tracking Protection feature & shouldn't be causing the problem either.

Thanks for the extra info on Ghostery having a whitelist/trusted option so that it can avoid breaking certain sites. Didn't know it had that. And also good to know that Ghostery doesn't break the site on Chrome.

The other addons I was worried you may have were ones like ClearURLs, Disconnect, NoScript and Privacy Badger and so on. But since you already tried Troubleshoot Mode that rules out all your addons since that mode disables all your addons.

Apologies, I missed where you said this: I have tried "Forget this site", I have tried all the proxy settings (I normally don't use a proxy), I have turned off the firewall (both on PC as well as in the router) but remember it works with Chrome and Edge. I tried turning off all the Firefox protections (fingerprinting, cookie blocking, etc.). I have cleared cookies, cache, etc. I tried creating a new profile. I tried doing it in a private window I tried Troubleshoot Mode (i.e., all add-ons disabled).

You really went above & beyond. Including changing DNS, switching internet source to mobile hotspot & killing off each background process one by one. I can't ask any more of you. :)

NoahSUMO,

I try to figure out things and fix things when I can. I am retired computer scientist. I started programming in 1962. Later developed the ARPANET, some Internet stuff, Unix systems, routers, etc. I gave a talk over at Mozilla in Mountain View in 2017. As you probably know, they have moved out of Mountain View and are in San Francisco now.

As I said earlier, Firefox is my preferred browser. I have tried a lot of browsers over the years (Mosaic, Netscape, Firefox, IE (various versions), Chrome, Edge, Duck Duck Go, and numerous others I don't even remember).

It is frustrating that more sites don't test with Firefox. Many just test with Chrome and Edge. And you said, addons, system issues, anti-virus software, etc., can all affect things. My frustrations are not so much that a site doesn't work, but that it doesn't work on Firefox.

Well I got it working. I don't particularly like my fix but it seems to work.

I changed the useragent in Firefox to the the one that Chrome uses. I opened Chrome and did a Google for what's my user agent. Google said: Your user agent Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/128.0.0.0 Safari/537.36

I overrode the Firefox useragent to that one and now it works. I will see how for how long. And I wonder what sites this might break.

Anyway, it sounds like a bug at Xfinity (i.e. Comcast).