Firefox Community Forum

NOTE: I have marked this as "Solved" because I figured out the problem described below, and I fixed it. See my following message here for a description of my solution.

Original message starts here ...

I'm using Firefox 144.0 under Debian Linux. I've used Firefox on this machine for years with no problem. Firefox can easily connect to literally thousands of web servers on the internet, both via HTTP and HTTPS.

But now, I'm having an issue:

I started running a web server on the same machine that Firefox is running on. This server only listens for non-HTTPS connections on port 80. I am not using any proxy server with Firefox.

I can easily and directly connect to my local web server's pages from my local machine from Chrome, w3m, curl, and direct telnet connections to port 80 ... all of which are addressing the publicly accessible domain name for my local web server. However, However, Firefox refuses to connect to any URL's on my local machine, and it gives me the following explanation:

Unable to connect

Firefox can’t establish a connection to the server at [ my server's domain name ].

   The site could be temporarily unavailable or too busy. Try again in a few moments.
   If you are unable to load any pages, check your computer’s network connection.
   If your computer or network is protected by a firewall or proxy, make sure that Firefox is permitted to access the web.

In Firefox, I have all auto-forcing of HTTPS disabled by means of Don’t enable HTTPS-Only Mode turned on.

I get the same error in Firefox whether I connect via a URL like "http://MYFULLDOMAINNAME" or a URL like "http://AAA.BBB.CCC.DDD", where "AAA.BBB.CCC.DDD" is my machine's publicly accessible static IP address and "MYFULLDOMAINNAME" is the long-standing, publicly accessible domain name for my machine ... both with and without a suffix of ":80" on the supplied URL.

And again, all other browsers on my machine have no problem whatsoever connecting to my own local web server on this same local machine of mine using those same URL's.

And all browsers (Firefox and otherwise) that are running on other machines all over the internet have no problem connecting to that same web server via the same URL's that I described above

Also, I have no firewall rules on my machine which would block access to my own machine's port 80.

What could be causing this error in Firefox, and what might I be able to do to fix it?

Thank you very much in advance.

UPDATE: Just a bit more information. Looking at the web logs, I see that Firefox's request never even reaches my local web server. In other words, Firefox itself is not even trying to make a TCPIP port 80 connection to my local web server in the first place

I had 128.7 esr installed and was getting crashes and upgraded to 128.8 esr and it was worse. Down graded to 128.0 esr and it seems to be working just fine so I will not be doing any further upgrades.

Yesterday, the Firefox quit working. Today my connection was verified by Fios and during the phone call, we tried Google Chrome (Yuck!) and it worked on the internet. I have downloaded the latest Firefox and it still does not work. Is there a problem with Firefox? Should I delete Firefox and reinstall?

when i open this website, it shows like this: https://in.tradingview.com/

Secure Connection Failed

An error occurred during a connection to in.tradingview.com. The OCSP response is not yet valid (contains a date in the future).

Error code: SEC_ERROR_OCSP_FUTURE_RESPONSE

   The page you are trying to view cannot be shown because the authenticity of the received data could not be verified.
   Please contact the website owners to inform them of this problem.

I received a notification that i could not connect to the internet without logging in. I tried the remedy suggested by other users (2020) and succeeded in removing this notification but still cannot access internet from my Mac computer. I have been a mozilla user for many years and have not encountered this oroblem before. All my other devices are working.

I have a secure private network on my CPU. Why does Firefox not allow my secure websites to remember this browser? The website gives me the option "Recognize this browser." I check that box. But it is a vicious cycle. There is such a thing as too much protection. This makes it time consuming to access my accounts, requiring a cell phone and code to access accounts. Please advise.

I am using 140 ESR version on linux with Cloudflare's DNS over HTTPS and with DOH active for some reason resolving a domain like d3oklwo3y1bx83.cloudfront.net will resolve to local host IP 127.0.0.1.

I am using firefox about:networking#dnslookuptool to test resolution of the domain d3oklwo3y1bx83.cloudfront.net Both with DOH on and off the resolution remains local host. I tried another browser on the same workstation and I was able to receive a resolution of 13.225.193.203 13.225.193.133 13.225.193.64 13.225.193.58 Why is firefox ESR not able to resolve that domain? What are causes ?

Is is firefox dnslookuptool results.

My home setup is such that I use PiHole for DNS (dual PiHoles). This includes doing DNS for my local network as well as black-hole for a bunch of Ad-serving domains. To get this to work with Firefox, I've gone through all the settings to turn off DNS over HTTPS (DoH). The documentation on this is in a multitude of places, and seems to have a lot of "this setting doesn't exist anymore" pointers, but I get it working... sort of.

Every few months (maybe every time Firefox updates?) Firefox stops seeing my local network names and starts showing ALL THE ADS. I go back through and LOOK AT THE SETTINGS (which ARE still set), but after LOOKING at the settings, it starts working as expected again for another however long. This has come to the point where I've stopped bothering to open Firefox when I need to get to my own network resources. DoH is already hard enough to turn off, but having to look it up every few months to "check" the settings so it's REALLY off is very difficult.

This has been going on for at least 8 months, and I'm only bothering to mention it now because I've noticed that I'm changing my habits, Goocrosoftle is winning.

So, MAYBE I'm still missing something. Half the articles point to settings that don't exist anymore, so maybe there's one more thing that will make this actually stick. Everything leading to the search HERE on this topic talks as if Firefox is still using the local machine's DNS, and that has not been the default for quite some time. Either way just adding my "inside." domain to the localdomains setting will not fix this problem.