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Very slow site loading due to Windows Firewall.
I'm experiencing the same problem as discussed in this cases that is not solved yet: https://support.mozilla.org/en-US/questions/1312836 https://support.mozilla.org/en-US/questions/1333547 https://support.mozilla.org/en-US/questions/1321038
Symptoms: After FF starting it loads pages fast enough. After several minutes of using pages start be loading very slow. Loading slowness increases until it becomes blocked continuously. Reload button has no effect. I tried everything from here: https://support.mozilla.org/en-US/kb/firefox-cant-load-websites-other-browsers-can - No effect.
Work around done: When windows is loading in Safe Mode the problem disappeared. If I disable Windows Defender Firewall the the problem disappear and appear after firewall enabling again in several minutes (same as after FF restarting) When I go to <current network settings> and switch Network Profile from Public to Private or from Private to Public the problem disappear but goes back just in several minutes (same as after FF restarting). Windows 10 Restorehealth has no effect, and reports that everything is OK with system files (DISM.exe /Online /Cleanup-image /Restorehealth ) The most strange thing Windows 10 In-place Upgrade has no effect.
I found out the core of problem is that Windows Firewall is blocking FF internal interprocess communication on local TCP ports. Yes, you would say it is not possible and firewall doesn't affect local port communication but in my case it is a fact. I used the ProcessMonitor from Windows Sysinternals, and Windows Defender Firewall with Advanced Security log. Screenshots shows this fact. On first two lines from Firewall log you see a Local Port Communication blocking, on ports 1401 and 1400. Next Screenshot from ProcessMonitor shows (see blue colored lines) that it was exactly FF communication, where I was trying to reload a page several times.
Any ideas what to do with it? It seems like Microsoft’s way fighting a concurrent web browsers, but I hope it isn’t.
Now I use FF version 94 but the problem starts from 88. I was trying FF downgrading to version 75 with no effect.
All Replies (7)
If I disable Windows Defender Firewall the the problem disappear and appear after firewall enabling again in several minutes . . . . I found out the core of problem is that Windows Firewall is blocking FF internal interprocess communication on local TCP ports.
You should try asking here: https://support.microsoft.com
But first, Some problems occur when your Internet security program was set to trust the previous version of Firefox, but no longer recognizes your updated version as trusted. Now how to fix the problem: To allow Firefox to connect to the Internet again;
- Make sure your Internet security software is up-to-date (i.e. you are running the latest version).
- Remove Firefox from your program's list of trusted or recognized programs. For detailed instructions, see
I use Windows Defender an it is up-to-date.
From link you sent i tried https://support.mozilla.org/en-US/kb/configure-windows-firewall-allow-firefox-access It says - "On the left side of the Windows Firewall panel, click Allow an app or feature through Windows Firewall. The Allowed apps panel will appear."
But on my Firewall Control Panel isn't such control.
See a screenshot please.
I have setup the Outbound Rule to allow any FF communication. It has no effect. The problem is the FF do not produce any HTTP requests due to the problem, so this feature can't have any effect.
Microsoft support advised me to make Windows 10 In-place Upgrade. I did it but it has no effect.
Keep after Microsoft support and keep us posted.
Suggestion: Remove All Firefox and Mozilla entries from the firewall.
Suggestion: Remove All Firefox and Mozilla entries from the firewall. Result - No effect.
I called for more help.
Hello everyone. I want to point out on one important thing once again. Windows Firewall DOESN'T block Outbound communication from FF. It blocks communication between FF processes on LOCAL PORTS. Windows Firewall is acting as a virus or malware and affects just one software product – FF.
I suspect if I raise a case to Microsoft support they will advise me to do Windows 10 In-place Upgrade. I have already done it with no effect. So it proves that OS files are not broken and it is a some kind of virus/malware. I’m afraid Microsoft will not want to solve this problem, why would they do? It is good for them when a virus affects exactly FF. It seems there is some hidden configuration that force Windows Firewall to act this way and this configuration is not a part of In-place Upgrade.
My main question what to do in this situation.
Mozilla corporation lost 46 million users in three years. May be this case will give a clue why. The Microsoft’s security software affects FF functionality, and do it such amazing way a user is experienced FF poor functionality – slowness and believes that it is certainly FF problem.
What is obvious user expected to think in this case? I believe he/she thinks: “FF become to be very bad browser. It is significantly slower than Edge or Chrome”
What is obvious user expected to do in this case? I believe he/she will switch to Edge or Chrome.
When I red cases on this site about my problem I saw I’m not only one who has this problem. But it seems I’m first who see why this is happening. I hope someone from Mozilla Firefox with power and willing would make attention on this case. I'm an advanced Windows user (c# developer) and can assists investigation.